JPH03177051A - Method and device for cutting semiconductor wafer - Google Patents

Abstract

PURPOSE:To prevent damage to a pellet to order to improve yield by leaving the surface of a semiconductor wafer bonded to a sheet as a continuous surface and cutting it vertically, and then supplying a fluid to between the soft adhesive sheet and a stage to cut the continuous surface for dividing it into a plurality of pellets. CONSTITUTION:A soft adhesive sheet 3, bonded and fixed to a fixing frame 4, is applied to the rear surface of a semiconductor wafer 1. Then, this sheet 3 is vacuum sucked and fixed on a stage 6 of a dicing device, around which stage 6 an enlarging ring 5 being set, and then vertical dicing is carried out by using a blade 7. This dicing does not effect complete cutting so that the surface of the wafer 1 bonded to the sheet is left uncut as a continuous surface. Next, the chucking is stopped and an enlarging ring presser 10 is lowered to press the frame 4, and then, when a fluid is supplied to between the sheet 3 and the stage 6, the sheet 3 is raised to break the uncut part of the wafer 1 to divide the wafer 1 into a plurality of pellets 2. Thereafter, the fluid is ejected and the ring presser 10 is further lowered to elongate the sheet 3 to keep apart the pellets 2 from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for cutting a semiconductor wafer.

<Prior art> The conventional method of dividing a semiconductor wafer into multiple pellets involves first pasting a soft adhesive sheet on the back side of the semiconductor wafer, then cutting the semiconductor wafer into individual pellets, and then cutting the back side into pellets. There is a method of expanding a soft adhesive sheet to separate pellets at predetermined intervals.

FIGS. 2(a) to 2(d) are cross-sectional views shown in order to explain an example of a conventional process of cutting by dicing and expanding a soft adhesive sheet. Also,
FIGS. 3(a) to 3(C) are cross-sectional views showing the state of the pellets and soft adhesive sheet in this step.

In this manufacturing method, first, as shown in FIG. 2(a),
Fixing the soft adhesive sheet 3 to a frame 4 made of stainless steel, etc.
Then, on this soft adhesive sheet 3,
The back side of the semiconductor wafer 1 is attached. Next, as shown in FIG. 2(b), the dicing device is
the blade 7 as shown in Figure 2 (C).
The semiconductor wafer 1 is diced and divided into a plurality of pellets 2. Through this step, as shown in FIG. 3(a), the semiconductor wafer 1 is completely cut into a plurality of pellets 2 on the soft adhesive sheet 3 through the cutting grooves 11.

Next, the pellets 2 and the soft adhesive sheet 3 are removed from the dicing device, washed and dried, and then set in a soft adhesive sheet expansion device as shown in FIG. 2(d), and heated while being expanded. Lower the ring presser 10 and expand the soft adhesive sheet 3.

However, in this method, the soft adhesive sheet 3 is stretched,
In order to enlarge and separate the pellets 2 at predetermined intervals, it was necessary to completely cut the semiconductor wafer 1 attached to the soft adhesive sheet 3. That is, as shown in FIG. 2(C), when dicing the semiconductor wafer 1 with the blade 7,
Not only the semiconductor wafer 1 but also the upper part of the sheet layer 3b is diced through the adhesive layer 3a of the soft adhesive sheet 3, and cutting grooves 11 are formed that reach the sheet layer 3b as shown in FIG. 3(a). was forming.

For this reason, the soft adhesive sheet 3 applies large frictional resistance to the blade 7 during dicing, shortening the life of the blade 7 and increasing costs. In addition, the adhesive of the adhesive layer 3a adheres to the surface of the blade 7, reducing the sharpness of the blade 7, and due to this adhesive, the frictional force against the semiconductor wafer 1 during dicing increases. Pellets 2, which had been cut into pieces, were sometimes blown away. Furthermore, since the soft adhesive sheet 3 is used as a support for the semiconductor wafer 1, when a force is applied partially to the semiconductor wafer 1 due to the cut made by the blade 7,
Semiconductor wafer 1 repeats partial deformation and restoration, resulting in minute vibrations, and due to this repetition of vibrations, pellets 2 are formed during dicing against the adhesive force! IJ l1il! I had something to do.

Also, during handling while removing from the dicing device and setting it on the soft adhesive sheet expanding device, as shown in Fig. 3(b)
As shown in Figure 2, adjacent pellets 2 collided with each other, resulting in chipped corners and 1' scratches.

Therefore, as shown in FIG. 3(C), the pellets 2 after expanding the soft adhesive sheet 3 include pellets 2a with chipped corners, resulting in a problem of low pellet yield. Ta.

In view of these problems, Japanese Patent Laid-Open No. 63-29948 proposes an improvement in the steps from dicing to pellet division in the manufacturing process of semiconductor devices.

Figures 4(a) and (b) are from Japanese Patent Application Laid-Open No. 63-29948.
FIG. 2 is a cross-sectional view showing a method of dividing a semiconductor wafer into a plurality of pellets disclosed in the above publication.

In this method as well, the steps of attaching and fixing the soft adhesive sheet 3 to the fixing frame 4 made of stainless steel or the like, and then attaching the back side of the semiconductor wafer 1 to the soft adhesive sheet 3 are the same as in the conventional method. It is. However, in this method, as shown in FIG. Then, the semiconductor wafer 1 is attached to the soft adhesive sheet 3 by vacuum suction, and then, by dicing,
As shown in FIG. 2(C), the semiconductor wafer 1 is divided into a plurality of pellets 2.

Next, as shown in Figure 4(b), turn off the vacuum suction and
By lowering the expansion ring presser 10, the soft adhesive sheet 3 is stretched and expanded to separate the pellets 2 at a predetermined interval, and then washed and dried.

The method disclosed in Japanese Patent Application Laid-Open No. 63-29948 solves the disadvantages of the conventional method, such as the time when the soft adhesive sheet 3 on which the pellets 2 are pasted is removed from the dicing device and set in the enlarging device. The problem of the pellet 2 being chipped or scratched due to handling has been solved. However, when dicing the semiconductor wafer 1, not only the semiconductor wafer 1 but also the upper part of the sheet layer 3b of the soft adhesive sheet 3 is diced. ilJ!
The problem of Iff etc. remains unsolved.

<Problems to be Solved by the Invention> The present invention has been made in view of the above-mentioned prior art, and includes a semiconductor wafer bonded to a soft adhesive sheet, at least the surface of the semiconductor wafer bonded to the sheet being a continuous surface. After cutting the semiconductor wafer vertically, that is, cutting the semiconductor wafer so that the cutting means does not contact the adhesive layer of the soft adhesive sheet, the semiconductor wafer is glued and fixed, and the soft adhesive sheet is transferred to the expansion device. A semiconductor wafer cutting method including a step of dividing a semiconductor wafer into a plurality of pellets and separating the pellets at a predetermined interval without cutting the semiconductor wafer, and a semiconductor wafer cutting apparatus suitable for carrying out the method. For the purpose of providing.

<Means for Solving the Problems> A first aspect of the present invention is to cut a semiconductor wafer bonded to a soft adhesive sheet vertically leaving at least the surface bonded to the sheet as a continuous surface. , supplying a fluid between the soft adhesive sheet and a stage on which the sheet is placed to cut the continuous surface, dividing the semiconductor wafer into a plurality of pellets, and then stretching the soft adhesive sheet. This is a method for cutting semiconductor wafers.

A second aspect of the present invention also provides a soft adhesive sheet to which a semiconductor wafer is adhered, a fixing means for stretching the sheet, a stage on which the sheet is laid, and a stage for stretching the sheet. A depressurizing means for adsorbing the sheet to the stage, a cutting means for cutting the semiconductor wafer, a fluid supply means for supplying fluid between the sheet and the stage, and an enlarging means for enlarging the sheet. The semiconductor wafer cutting apparatus is characterized in that the stage is provided with a pressure reduction port communicating with the pressure reduction means and a fluid supply port communicating with the fluid supply means on its surface.

Functions> The functions of the semiconductor wafer cutting apparatus according to the present invention are as follows.

That is, first, the soft adhesive sheet, which is stretched by the fixing means and to which the semiconductor wafer is adhered, is adsorbed and fixed to the stage surface of the cutting device of the present invention by the decompression means.

Next, the semiconductor wafer is cut vertically, leaving at least the surface of the wafer adhered to the soft adhesive sheet as a continuous surface so that the adhesive does not adhere to the cutting means.

Once cutting is complete, turn off the vacuum and use the fluid supply means to
A fluid is supplied between the soft adhesive sheet and the stage surface through the fluid supply port, and the continuous surface of the semiconductor wafer is cut into a plurality of pellets by the fluid pressure.

After removing the fluid, the flexible adhesive sheet is stretched to separate the plurality of pellets.

Thereby, the semiconductor wafer can be cut and divided into a plurality of pellets of a predetermined size without moving the soft adhesive sheet to which the semiconductor wafer is adhered during the process.

<Example> Hereinafter, preferred embodiments will be shown and the present invention will be explained in detail.

First, a method for cutting a semiconductor wafer according to the first aspect of the present invention will be explained based on the drawings.

7isI Figures (a) to (f) are sectional views for explaining a preferred embodiment of the first aspect of the present invention.

In the method of the present invention, first, as shown in FIG. 1(a), a soft adhesive sheet 3 bonded and fixed to a fixing frame 4 is attached to the back surface of a semiconductor wafer 1. next,
As shown in FIG. 1(b), a semiconductor wafer 1 is placed on a stage 6 of a dicing machine equipped with a soft adhesive sheet enlarging mechanism, in which an enlarging ring 5 is set around the stage 6.
The soft adhesive sheet 3 to which is pasted is fixed by vacuum suction using a vacuum pump 8, and then vertically diced using a blade 7.

At this time, the fixing frame 4 is supported by a support member (not shown), and the enlarging ring presser 10 used in the subsequent process is removed as shown. In addition, the degree of vacuum at this time is 400 to 500 m
About mHg is preferable. When dicing the semiconductor wafer 1, as shown in FIG. 1(c), the semiconductor wafer 1 is not completely cut, but a small amount is left so that the surface of the semiconductor wafer 1 bonded to the soft adhesive sheet 3 remains as a continuous surface. This uncut amount is 0.5 to 0.5 mm thick for a typical semiconductor wafer.
Since it is 6 mm, it is usually best to leave 10 to 50 μm.
Considering the division of semiconductor wafer 1 in the next process, 2
Approximately 0 μm is optimal.

Next, move the three-way valve 14 to cut off the suction by the vacuum pump 8, and as shown in FIG.
0 is lowered and the fixing frame 4 is pressed down, when a fluid such as water is supplied between the soft adhesive sheet 3 and the stage 6 using means such as the pump 9, the soft adhesive sheet 3 is lifted and the soft adhesive is removed. The uncut portion of the semiconductor wafer 1 adhered to the sheet 3 is broken, and the semiconductor wafer 1 is divided into a plurality of pellets 2 as shown in FIG. 1(f).

Thereafter, the supplied fluid is discharged, and as shown in FIG. 1(e), the expanding ring presser 10 is further lowered to stretch and expand the soft adhesive sheet 3, and the pellets 2 are pulled apart at a predetermined distance. After separating, wash and dry.

Although the preferred embodiments of the semiconductor wafer cutting method of the present invention have been described above, the method of the present invention is not limited thereto.

That is, the soft adhesive sheet does not need to be fixed to the stage surface by vacuum suction using a fixing frame and a vacuum pump, as long as the soft adhesive sheet is stretched over the stage.
In addition, cutting semiconductor wafers is not limited to the dicing method.
A scribing method or a laser beam may also be used. Furthermore, the stretching of the soft adhesive sheet is not limited to one time,
For example, after enlarging the left and right sides, the image may be enlarged perpendicularly to the enlargement direction, that is, front and back. Furthermore, instead of stretching the soft adhesive sheet by pushing down the fixing frame, it may be stretched in the horizontal direction.

Next, a semiconductor wafer cutting apparatus according to a second aspect of the present invention will be described based on the drawings.

The cutting device of the present invention is a device in which a semiconductor wafer cutting mechanism and a soft adhesive sheet expanding mechanism are integrated, and the semiconductor wafer is bonded to the soft adhesive sheet on the surface thereof;
A fixing means for stretching the sheet, a stage on which the sheet is laid, a depressurizing means for adsorbing the sheet to the stage, a cutting means for cutting the semiconductor wafer, and the sheet and the stage. The stage has a fluid supply means for supplying fluid between the stages, and an enlarging means for enlarging the sheet, and the stage has a decompression port communicating with the decompression means on its surface and a decompression port communicating with the fluid supply means. It has a fluid supply port that communicates with it.

Explaining based on FIG. 1(b) which is a preferred embodiment,
The cutting device of the present invention includes a fixing frame 4, a stage 6, a blade 7, a vacuum pump 8, a pump 9, and a three-way valve 14 as members related to the cutting mechanism, and an enlargement ring 5 and a three-way valve 14 as members related to the enlargement mechanism. There is a ring presser 10 for expansion, and there is also a soft adhesive sheet 3 related to both mechanisms.

Each member will be explained.

The soft adhesive sheet 3 is a sheet that can adhere the semiconductor wafer 1 to its surface and can be stretched.

The material of the sheet itself is synthetic resin such as polyvinyl chloride, polyester, polyolefin, etc., and on its side,
It is made up of layers of adhesive that can bond the semiconductor wafer 1 together. The total thickness of the sheet is preferably about 100 μm, and the thickness of the adhesive layer is preferably about 5 to 20 μm.

The size and shape of the soft adhesive sheet 3 are limited by the size, shape, and expansion mechanism of the stage 6, which will be described later, but generally the size and shape of the fixing frame 4, which will be described later, are located on the outer periphery of the stage 6. , the same as the shape.

The fixing frame 4 is used to stretch the soft adhesive sheet 3 prior to adhering the semiconductor wafer 1, and to prevent the fluid supplied between the soft adhesive sheet 3 and the stage 6 from flowing out by the fluid supply means described later. This is a fixing means for fixing the soft adhesive sheet 3 in order to prevent this. Therefore, when the soft adhesive sheet 3 is fixed, it is positioned on the outer peripheral portion of the stage 6, which will be described later, or on the surface of the stage 6.

The fixing frame 4 is a frame having a hollow part,
It is preferable that the shape of the hollow portion is similar to the surface shape of the stage 6 described later, but it does not have to be the same as the surface shape of the stage 6 if the enlarging method of the enlarging means described later is horizontal. The size of the hollow part should be approximately the same as or slightly larger than the surface of the stage 6, which will be described later. However, if the enlarging method of the enlarging means is horizontal, It may be smaller than the size. However, the hollow part is located on the semiconductor wafer 1.
It's more like a dog. The width of the frame is sufficient as long as it can fix the soft adhesive sheet 3, and is usually about 15 to 20 mm.

The fixing frame 4 fixes the soft adhesive sheet 3, and when the soft adhesive sheet 3 is stretched, it comes into contact with an arm 20 portion of an enlarging ring presser 10 of the stretching means described later. Therefore, if the stage to be described later has a cylindrical or prismatic portion and the soft adhesive sheet 3 is stretched by pushing down the fixing frame 4 along the side surface of the cylindrical or prismatic portion, the stretching will be done in one go. Therefore, the fixing frame 4 may be made of one piece, but the stage 6 may have a conical or square pedestal portion instead of a cylindrical or prismatic portion,
When the fixing frame 4 is pushed diagonally downward along the slope and stretched, or when the soft adhesive sheet 3 is stretched horizontally, the fixing frame 4 can be divided into four parts, for example. .

In FIG. 1(b) which is a preferred embodiment, the fixing frame 4
is an annular frame having a circular hollow part, and the size of the hollow part is slightly larger than the size of the surface of the stage 6.

In addition, when the fixing frame 4 is located on the outer periphery of the stage 6, which will be described later, the fixing frame 4 is used for other purposes (not shown) during the period from when the soft adhesive sheet 3 is fixed to the surface of the stage 6 until just before the stretching is performed. It is supported by the following members.

The stage 6 is a stand that supports the soft adhesive sheet 3,
In addition, the fixing frame 4 may also be supported, and a soft adhesive sheet 3 is laid on the surface thereof, and furthermore, a pressure reduction port communicating with a pressure reduction means described later and a fluid supply means also described later are provided on the surface. It has a fluid supply port that communicates with the fluid supply port.

The shape of the stage 6 itself is such that the surface on which the soft adhesive sheet 13 is laid is a cylinder, a prism, a cone, a rectangle, etc., and the surface is horizontal, and when the soft adhesive sheet 3 is stretched, A shape that can be stretched uniformly is preferred, and a cylinder is particularly preferred. Moreover, the stage 6 may be comprised only of the part which comprises the surface on which the soft adhesive sheet 3 is laid|laid.

In FIG. 1(b), which is a preferred embodiment, the stage 6 has a stepped cross-sectional shape, and the small diameter portion (the soft adhesive sheet 3
It consists of a large diameter part (the part that constitutes the surface on which the pipe is laid) and a large diameter part.

The size of the stage 6 may be such that its surface area is larger than the cross-sectional area of the semiconductor wafer 1 to be cut.

By the way, the semiconductor wafer cutting apparatus of the present invention is characterized in that it has a pressure reduction port and a fluid supply port on the surface of the stage 6.

The pressure reduction port is connected to the pressure reduction means described later, and the fluid supply port is connected to the pressure reduction means described below.
The decompression port and the fluid supply port are, for example, slits or pipe openings provided in the stage 6, or a part of the stage is made of a porous material such as ceramics. This is the hole obtained by

The pressure reduction port and fluid supply port may be used together, or the pressure reduction port and fluid supply port may be used together.
Each of the fluid supply ports may be provided, and the pressure reduction port may be provided at least in the portion of the surface of the stage 6 where the semiconductor wafer 1 is placed.
is adsorbed and fixed to the surface of the stage 6, so it is better to provide multiple decompression ports at positions where a homogeneous suction force is applied.Furthermore, only one fluid supply port may be provided at the center of the surface of the stage 6. However, there may be a plurality of them. In the case of a plurality of them, it is preferable to provide them at a position where a uniform fluid pressure is applied to the soft adhesive sheet 3 and the semiconductor wafer 1.

The pressure reducing means is, for example, a vacuum pump. This pressure reducing means communicates with a pressure reducing port on the surface of the stage 6. However, the pressure reducing means in the present invention is not limited to a member capable of reducing pressure such as a vacuum pump, and is used in equipment that has only a part where a member capable of reducing pressure is installed and does not have a member capable of reducing pressure. It also refers to the area where a member that can reduce pressure is installed.

As shown in FIG. 1(b), when the stage 6a is made of a porous material, the holes in the porous material and the vacuum pump 8 are connected to the passage 15 (in charge of the pressure reducing pipe) provided in the stage 6b. do)
It is preferable to communicate through the

The fluid supply means is, for example, a pump, and is a means that can supply fluid such as water between the soft adhesive sheet 3 and the surface of the stage 6 through a fluid supply port. The fluid supply means communicates with a fluid supply port on the surface of the stage 6.

The fluid supply means in the present invention, as in the case of the pressure reduction means described above, has only a part where a member capable of supplying fluid is installed, and is capable of supplying fluid in an apparatus that does not have a member capable of supplying fluid. It also refers to the part where the parts are installed.

In the example of FIG. 1(b) which is a preferred embodiment, the fluid supply port is a pressure reducing port, and the fluid supply port and the fluid supply means (pump 9
) is shared with the passage 15, which is a pressure reducing pipe that communicates the pressure reducing port and the pressure reducing means (vacuum pump 8), and the switching is performed by the three-way valve 14.
However, the pressure reducing pipe and the fluid supply pipe may be provided separately, and it goes without saying that two valves may be provided, one for each of the pressure reducing means and the fluid supply means.

The cutting means is a means for cutting the semiconductor wafer 1, and any means that can precisely position the semiconductor wafer 1 and cut the semiconductor wafer 1 to a desired depth can cut the semiconductor wafer 1.
Any means used for cutting may be used.

Examples of cutting methods include a blade dicing method, a diamond scribing method, and a laser method.

The example shown in FIG. 1(b) is a blade dicing method, and the cutting means is composed of a blade 7, a blade moving mechanism, and a blade rotating mechanism (not shown).

The blade 7 is a member that cuts the semiconductor wafer 1, and the blade moving mechanism is a mechanism that changes the direction of the blade 7 and moves the blade 7 back and forth and left and right.
That is, it is a mechanism for changing the direction of the blade 7 in the air above the semiconductor wafer 1 and moving the blade 7 to position the blade 7 at the cutting position of the semiconductor wafer 1, but the specific driving means thereof is not limited and is generally known. It's fine to use one. The blade rotation mechanism is a mechanism that rotates the blade 7 to cut the semiconductor wafer 1, and a motor or the like can be cited as a specific driving means thereof.

The stretching means is not particularly limited as long as it can uniformly stretch the soft adhesive sheet 4.

Referring to FIG. 1(b), which is a preferred embodiment, the enlarging means is composed of an enlarging ring 5, an enlarging ring presser 10, and a drive mechanism for moving the enlarging ring presser 10 (not shown). There is. In the figure, the part of the stage 6 that constitutes the surface on which the soft adhesive sheet 3 is laid is a small-diameter cylindrical part, below which there is a large-diameter cylindrical part, and the small-diameter cylindrical part of the stage 6 is a small-diameter cylindrical part. An enlarging ring 5 is installed from the outer periphery of the portion to the surface of the large-diameter cylindrical portion. Along this expanding ring 5, a circular soft adhesive sheet 3 is attached to the fixing frame 4 on its arm 20.
It is designed to be stretched vertically downward by the enlarging ring presser 10 that is in contact with the enlarging ring.

The shape and size of the enlarging ring 5 and the enlarging ring presser 10 are determined according to the shape and size of the stage 6. Further, the drive mechanism for moving the enlarging ring presser 10 is not limited, and may be, for example, a motor.

As other enlargement means, the following examples are also possible.

In this example, the part constituting the surface on which the soft adhesive sheet 3 of the stage 6 is laid is a conical or square base, and the fixing frame 4 is mounted diagonally along the slope of the conical or square base. This method uses an enlargement ring presser 10 that can be pushed down. In this example, when the enlarging ring presser 10 is pushed down, the arm 20 portion of the enlargement ring presser 10 is configured to drop diagonally downward.

Furthermore, as another example, means for stretching the soft adhesive sheet 3 in the horizontal direction is also possible. In this example, it is only necessary that the arm portions of the enlargement member, which replaces the enlargement ring presser 10, sandwich the fixing frame 4 and extend in the horizontal direction. In this case, the shape of the stage 6 is not limited at all as long as it has a horizontal surface, but the shape of the fixing frame 4
For this, use one that can be divided, preferably one that can be divided into four parts.

Each member of the cutting device of the present invention is as described above, but any member is not limited to this, and it goes without saying that it can be replaced with other members having similar functions.

Next, regarding the operation of the preferred embodiment of the cutting device of the present invention,
This will be explained based on FIG.

In the present invention, the semiconductor wafer 1 is placed on the soft adhesive sheet 3 stretched and adhered to the fixing frame 4 (the first
(a)), at the same time, the soft adhesive sheet 3 is placed on the stage 6, and the fixing frame 4 is supported by a support member (not shown), and then the vacuum pump 8 is activated. As a result, the semiconductor wafer 1 is fixed (FIG. 1(b)).

Next, the semiconductor wafer 1 is cut by the blade 7 at predetermined intervals. In addition, at this time, so that the surface of the semiconductor wafer 1 bonded to the soft adhesive sheet 3 remains continuous,
Cut vertically leaving a portion (Fig. 1 (C)).

After cutting is completed, the blade 7 and other cutting means are removed. Next, lower the enlarging ring presser 10 to press the fixing frame 4, and move the three-way valve 14.
The communication between the stage 6a (made of porous material) and the vacuum pump 8 is cut off, and the stage 6a and the pump 9 are made to communicate with each other. Then, when fluid is supplied from the pump 9 between the soft adhesive sheet 3 and the stage 6 and the soft adhesive sheet 3 is lifted, the semiconductor wafer 1 is divided into pellets 2 by the fluid pressure (Fig. 1(d) )).

The pump 9 sucks and collects the supplied fluid. Thereafter, when the enlarging ring presser 10 is lowered, the soft adhesive sheet 3 is stretched and stretched, thereby increasing the distance between the pellets 2 (FIG. 1(e)). Note that FIG. 1(f) is an enlarged view of the pellet 2 and soft adhesive sheet 3 portions in FIG. 1(d).

<Effects of the Invention> According to the present invention, a semiconductor wafer with a soft adhesive sheet attached to the back side is cut on the stage of a cutting device having means for stretching the soft adhesive sheet, so that the surface of the semiconductor wafer bonded to the soft adhesive sheet is continuous. After cutting the wafer, leaving a portion intact, fluid is supplied between the soft adhesive sheet and the stage to divide the semiconductor wafer, and the soft adhesive sheet is then stretched to space the pellets at predetermined intervals. Since the semiconductor wafers are separated, there is no need to transfer the soft adhesive sheet to which the semiconductor wafer is pasted from the cutting device to the expanding device.Therefore, the pellets do not come into contact with each other until the separation into pellets is completed.
The pellet yield is improved without chipping of the corners of the pellets or damage to the pellets.

Further, according to the present invention, when cutting the semiconductor wafer, the semiconductor wafer is not completely cut to the lower end thereof, so the cutting member such as the blade does not come into contact with the adhesive layer of the soft adhesive sheet, and therefore the cutting member The lifespan of the sheet is extended, costs can be reduced, and the pellets are difficult to peel off from the soft adhesive sheet during cutting, so the pellets are not thrown off by the cutting member, and the yield of the pellets is improved.

[Brief explanation of drawings]

Figure 1 (a) (b) (c) (d), (e)
and (f) are cross-sectional views for explaining one embodiment of the present invention. Figure 2 (a), (b), (C) and (d) and Figure 4
Figures (a) and (b) are cross-sectional views for explaining a conventional dicing and enlarging method. Moreover, FIGS. 3(a), 3(b), and 3(C) are cross-sectional views for explaining the state of pellets when performing the conventional dicing and expanding method. Explanation of symbols 1...Semiconductor wafer, 2...Pellet, 3...Soft adhesive sheet, 3a...Adhesive layer. 3b...Seat, 4...Fixing frame, 5...Enlargement ring, 6.6a, 6b...Stage, 7...Blade, 8...Vacuum pump, 9...Pump , 10... Enlargement ring holder, 11... Cutting groove, 14... Three-way valve, 15... Passage, 20... Arm F I G, 1 FIG, 2 F f G, 3

Claims (2)

[Claims] (1) After cutting a semiconductor wafer adhered to a soft adhesive sheet vertically leaving at least the side of the semiconductor wafer adhered to the sheet as a continuous surface, a gap between the soft adhesive sheet and the stage on which the sheet is installed. A method for cutting a semiconductor wafer, comprising supplying a fluid to cut the continuous surface, dividing the semiconductor wafer into a plurality of pellets, and then stretching the soft adhesive sheet. (2) A soft adhesive sheet to which the semiconductor wafer is adhered, a fixing means for stretching the sheet, a stage on which the sheet is laid, and a decompression means for adsorbing the sheet to the stage. a cutting means for cutting the semiconductor wafer; a fluid supply means for supplying fluid between the sheet and the stage; and an enlarging means for enlarging the sheet. A semiconductor wafer cutting apparatus characterized in that a surface thereof is provided with a pressure reduction port communicating with the pressure reduction means and a fluid supply port communicating with the fluid supply means.