JP3482157B2 - Semiconductor wafer dicing method and semiconductor wafer dicing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer dicing method and a semiconductor wafer dicing apparatus for processing a semiconductor wafer into a desired semiconductor chip size.

[0002]

2. Description of the Related Art In recent years, LED semiconductor chips used for LED lamps have been rapidly used for various purposes such as being used as a backlight of a key portion of a mobile phone, and cost reduction and miniaturization are required.

GaP, GaAsP, GaAs are examples of light emitting element materials used in such LED lamps.
And compound semiconductors such as GaAlAs.
As a method of cutting these semiconductor wafers into a plurality of semiconductor chips to obtain a desired semiconductor chip shape, the semiconductor wafer is attached onto a dicing sheet, and the semiconductor wafer is completely removed in the thickness direction by a blade rotating at high speed. There is a method called full dicing for cutting. Figure 6
FIG. 4 is a diagram showing a conventional typical dicing method for a semiconductor wafer.

The dicing apparatus 1 includes a dicing table 8 for fixing a dicing sheet 7 to which the semiconductor wafer 6 is attached, a blade 2 for rotating the semiconductor wafer 6 at high speed to cut the semiconductor wafer 6, and a dicing table facing the cutting position of the semiconductor wafer 6. And a cooling liquid discharge port 14 for discharging the cooling liquid.

The semiconductor wafer 6 is first cut by the blade 2 in parallel with the imaginary line 11 in the first direction at intervals of 0.2 mm. After that, the dicing table 8 is rotated by 90 ° about the axis 21 and is cut a plurality of times at intervals of 0.2 mm in parallel with an imaginary line 12 that is a second direction perpendicular to the first direction. Semiconductor chip 20
Split into. At this time, the dicing sheet 7 is cut in the thickness direction, and the semiconductor wafer 6 is completely cut in the thickness direction. Further, in order to completely cut the semiconductor wafer 6 to the periphery, an imaginary line 13 larger than the diameter of the semiconductor wafer 6 is used.
The cutting operation is performed by moving the blade 2 to a range surrounded by. During the cutting operation, the cooling liquid is discharged from the cooling liquid discharge port 14 toward the cutting position of the semiconductor wafer 6 at a constant flow rate to cool the blade 2 and wash away the cutting powder of the semiconductor wafer 6.

[0006]

Since the blade 2 is rotated at a high speed of, for example, about 30,000 rpm to cut the semiconductor wafer 6, the blade 2 deteriorates to a very high temperature due to frictional heat during the cutting operation. . In order to prevent this, during the cutting of the semiconductor wafer 6, the cooling liquid is constantly discharged to the cutting position of the blade 2. Also, with this,
Cutting powder of the semiconductor wafer 6 is also eliminated. The cooling liquid contacting the blade 2 is discharged at a high speed in the rotating direction of the blade at the cutting position. That is, in FIG. 6, when the blade 2 is rotating clockwise, the cooling liquid is discharged in the direction of arrow 24 (left side of FIG. 6).

The blade 2 reciprocates in the directions of arrows 22 and 23 in FIG. 6 (left and right directions in FIG. 6) to cut the semiconductor wafer 6. In order to surely cut the semiconductor wafer 6 to the periphery as described above, after moving the blade 2 in the direction of the arrow 22 to completely cut the semiconductor wafer 6 to the periphery, the imaginary line 1
It is necessary to move the blade 2 further up to 3. During this time, the cooling liquid discharged at high speed is sprayed on the periphery of the semiconductor wafer 6, so that the cut and divided semiconductor chips 20 are peeled off from the dicing sheet 7. As a result, as shown in FIG. 7, the semiconductor chips 20 on the peripheral edge of the semiconductor wafer 6 on the arrow 22 side are peeled off and blown off, and the yield is reduced.

The separated semiconductor chips 20 are blown to the central portion of the semiconductor wafer 6 by the cooling liquid sprayed at a high speed, and the semiconductor chips 20 in the central portion of the semiconductor wafer 6 are also damaged, so that the yield is further reduced. Further, the peeled semiconductor chip 20 hits the blade 2, and the blade 2 is chipped. As described above, the conventional technique has a problem that the yield is low and the processing cost is high.

Particularly, in a semiconductor chip used for an LED lamp, the size of the top surface of the semiconductor chip is 0.
Since the dicing is performed to be 20 mm or less and 0.20 mm or less in width, the contact area between one semiconductor chip 20 and the dicing sheet 7 becomes very small, and the semiconductor chip is easily peeled off by the cooling liquid discharged at high speed. It

For example, the dicing interval is 0.25 mm
When the dicing is performed, the size of the divided semiconductor chip is about 0.22 mm in length and 0.22 mm in width. When the dicing interval is 0.20 mm, the size of the divided semiconductor chip 20 is about 0.17 m in length.
m, horizontal 0.17 mm. Therefore, the contact area between one semiconductor chip 20 diced at a dicing interval of 0.20 mm and the dicing sheet 7 is 0.02.
This is 89 mm ² , and the contact area between one semiconductor chip 20 diced at a dicing interval of 0.25 mm and the dicing sheet 7 is 0.0484 mm ² . That is, the contact area of the semiconductor chips 20 diced at the dicing interval of 0.20 mm is equal to the dicing interval of 0.25.
About 6 of the contact area of the semiconductor chip diced by mm
It will be 0%. As described above, as the dicing interval is made smaller, the contact area between one semiconductor chip and the dicing sheet 7 becomes smaller in proportion to the square of the dicing interval, and the semiconductor chip 20 is easily peeled off from the dicing sheet 7, resulting in a higher yield. descend.

When the dicing sheet 7 having a strong adhesive force is used, peeling of the semiconductor chip 20 is prevented,
The stress applied to the semiconductor chip 20 increases, and the semiconductor chip 20 is cracked or chipped. Further, when the dicing sheet 7 having a strong adhesive force is used when performing the process after dicing, there is a problem that working efficiency is lowered.

The prevention of separation of the semiconductor chip 20 by the cooling liquid as described above can be improved by reducing the flow rate of the cooling liquid, but in this case, the cooling effect of the blade 2 is reduced and the blade 2 is sufficiently It is not cooled down and becomes severely deteriorated.

An object of the present invention is to provide a semiconductor wafer dicing method and a semiconductor wafer dicing apparatus capable of preventing the semiconductor chips from being peeled off by a cooling liquid during dicing of the semiconductor wafer and improving the yield. .

[0014]

According to the present invention, there is provided a dicing table for fixing a dicing sheet having a semiconductor wafer attached thereto, a cutting device having a blade for rotating the semiconductor wafer to cut the semiconductor wafer, and a cutting position for the semiconductor wafer. A cooling liquid discharging device for discharging the cooling liquid toward the cutting device, and a control device for controlling the cutting device and the cooling liquid discharging device. The semiconductor wafer attached on the dicing sheet is predetermined by the blade in the first direction and In a dicing method for a semiconductor wafer, in which a dicing sheet is cut and cut a plurality of times in parallel to a second direction perpendicular to the first direction, and the semiconductor wafer is divided into a plurality of semiconductor chips. The control device has a cooling liquid flow rate adjusting device for adjusting the flow rate, and the control device performs cutting work of the peripheral portion of the semiconductor wafer. Utoki a dicing method of a semiconductor wafer, characterized in that to reduce the discharge flow rate of the cooling fluid.

[0015]

According to the present invention, the semiconductor wafer to be cut is attached on the dicing sheet and fixed on the dicing table. The cutting device has a rotating blade, and the rotating blade cuts the semiconductor wafer on the dicing sheet in parallel to a predetermined first direction and a second direction perpendicular to the first direction until the dicing sheet is cut a plurality of times. It is cut and divided into a plurality of semiconductor chips.

At the cutting position of the semiconductor wafer, the cooling liquid is discharged from the cooling liquid discharging device to wash away the cutting powder of the semiconductor wafer and cool the blade. The cooling liquid discharge device and the cutting device are controlled by the control device.
The cooling liquid discharge device has a cooling liquid flow rate adjusting device for adjusting the discharge flow amount of the cooling liquid, and the control device changes the discharge flow amount of the cooling liquid during the cutting operation.

When the semiconductor chip is peeled off from the dicing sheet and the peripheral portion of the semiconductor wafer is easily cut off, the controller reduces the discharge flow rate of the cooling liquid. This reduces the amount of cooling liquid that hits the semiconductor chips on the periphery of the semiconductor wafer, so that the semiconductor chips are less likely to be peeled off from the dicing sheet, the semiconductor chips are prevented from flying, and the yield is improved. Further, when cutting the inside of the semiconductor wafer, the discharge flow rate of the cooling liquid is still high, so that the cooling effect of the blade 2 is not reduced and deterioration is suppressed. In addition, it is possible to use a dicing sheet with the best adhesive strength, you do not have to use a strong adhesive dicing sheet, and there is no large stress on the semiconductor chip, so you can prevent cracking or chipping of the semiconductor chip You can In addition, workability in the steps after the dicing step is also improved.

Further, according to the present invention, the control device reduces the flow rate of the cooling liquid when the blade reaches the periphery of the semiconductor wafer when cutting the semiconductor wafer parallel to the second direction. It is characterized by controlling the flow rate adjusting device.

According to the present invention, when the blade reaches the periphery of the semiconductor wafer, the control device controls the cooling liquid flow rate adjusting device to decrease the cooling liquid flow rate.
The blade cooling effect is reduced for a minimum period of time, deterioration of the blade can be minimized, semiconductor chips are prevented from flying, and the yield is improved.

Further, the present invention has an image recognition device for recognizing the shape of the semiconductor wafer, and the control device adjusts the flow rate of the cooling liquid based on the recognized shape of the semiconductor wafer.

According to the present invention, by the image recognition device,
Since the controller recognizes the shape of the semiconductor wafer and the controller adjusts the flow rate of the cooling liquid based on the recognized shape of the semiconductor wafer, for example, when the blade cuts the peripheral portion of the semiconductor wafer, the discharge flow rate must be reliably reduced. When the blade comes off this peripheral portion, the discharge flow rate is rapidly increased, so that deterioration of the blade can be minimized, semiconductor chips can be prevented from flying, and the yield can be improved.

Further, according to the present invention, the size of the top surface of the divided semiconductor chip is 0.20 mm or less in length and 0.2 in width.
It is characterized by being a quadrangle of 0 mm or less.

According to the present invention, when the top surface of the divided semiconductor chip is a quadrangle having a length of 0.20 mm or less and a width of 0.20 mm or less, the contact area between the dicing sheet and the semiconductor chip is extremely large as described above. The size of the semiconductor chip has become small, and the semiconductor chip is easy to fly in the conventional technology. According to the present invention, even in such a case, the semiconductor chips are reliably prevented from jumping, and the yield is greatly improved.

Further, according to the present invention, the control device controls the discharge flow rate of the cooling liquid to be 0.4 liters per minute or more and 0.6 liters or less per minute when cutting the peripheral portion of the semiconductor wafer, When cutting, the discharge flow rate of the cooling liquid is set to 0.7 liters per minute or more and 0.9 liters or less per minute.

According to the invention, the control device cuts the inside of the semiconductor wafer by setting the discharge flow rate of the cooling liquid to 0.4 liters per minute or more and 0.6 liters or less when cutting the peripheral portion of the semiconductor wafer. At that time, the discharge flow rate of the cooling liquid is set to 0.7 liters per minute or more and 0.9 liters or less.

When the semiconductor wafer is cut by such a method, the semiconductor chips are hardly jumped, cracked or chipped, the yield is dramatically improved, and the reduction in the life of the blade is suppressed.

Further, according to the present invention, a dicing table for fixing a dicing sheet to which a semiconductor wafer is attached, a cutting device having a blade for rotating and cutting the semiconductor wafer, and a cooling liquid directed toward a cutting position of the semiconductor wafer. A cooling liquid discharging device for discharging and a control device for controlling the cutting device and the cooling liquid discharging device are provided, and the semiconductor wafer stuck on the dicing sheet is cut by a blade in a predetermined first direction and in a direction perpendicular to the first direction. In a dicing method for a semiconductor wafer in which a dicing sheet is cut and cut a plurality of times to divide into a plurality of semiconductor chips in parallel with each other in the second direction, the cooling liquid discharging device is a cooling device that adjusts a discharge flow rate of the cooling liquid. A liquid flow rate adjusting device, the control device, when performing a cutting operation of the peripheral portion of the semiconductor wafer, A dicing apparatus of the semiconductor wafer, characterized in that to reduce the discharge flow rate of 却液.

According to the present invention, the semiconductor wafer to be cut is attached on the dicing sheet and fixed on the dicing table. The cutting device has a rotating blade, and the rotating blade cuts the semiconductor wafer on the dicing sheet into the dicing sheet in parallel in a predetermined first direction and in a second direction perpendicular to the first direction, and cuts a plurality of times. Then, it is divided into a plurality of semiconductor chips.

The cooling liquid discharging device and the cutting device are controlled by the control device. The cooling liquid discharge device has a cooling liquid flow rate adjusting device for adjusting the discharge flow amount of the cooling liquid, and the control device changes the discharge flow amount of the cooling liquid during the cutting operation.

At the cutting position of the semiconductor wafer, the cooling liquid is discharged from the cooling liquid discharging device to wash away the cutting powder of the semiconductor wafer and cool the frictional heat of the blade.
The cooling liquid discharge device has a cooling liquid flow rate adjusting device, and the control device is changed by the cooling liquid flow rate adjusting device during the cutting operation.

For example, when performing a cutting operation on the peripheral portion of the semiconductor wafer where the semiconductor chips are easily peeled off from the dicing sheet and fly, the controller reduces the discharge flow rate of the cooling liquid. As a result, the semiconductor chips are less likely to peel off from the dicing sheet until the amount of the cooling liquid that hits the semiconductor chips around the periphery of the semiconductor wafer is reduced, the semiconductor chips are prevented from flying, and the yield is improved.
Further, when the inside of the semiconductor wafer is cut, the discharge flow rate of the cooling liquid remains high, so that the cooling effect of the blade 2 is not reduced and deterioration is suppressed.

[0033]

1 is a schematic view showing the structure of a dicing device 32 according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a cutting device 54. Dicing device 32
Is a cutting device 54, a dicing table 43 on which a semiconductor wafer 41 such as a semiconductor wafer is mounted, an image input device 38 for picking up a planar shape of the semiconductor wafer 41, an operation unit 55 for inputting dicing conditions, and a semiconductor wafer. 41
A cooling liquid discharge device 34 for discharging the cooling liquid to the cutting position of
And a control device 39 for controlling the dicing device 32.

As shown in FIG. 2, the cutting device 54 includes a blade 33 having an ultrathin disc shape and a cutting blade on the outer circumference, and
And a housing 35 that rotatably supports the blade 33 by a rotary shaft 36 having an axis line perpendicular to the plane of FIG.

The cooling liquid discharge device 34 is mounted on the housing 35 and discharges the cooling liquid toward the cutting position of the semiconductor wafer 41, and the cooling liquid flow rate adjusting device for adjusting the flow rate of the cooling liquid. 40 and cooling liquid discharge port 5
Flow path 3 connecting 6, 59 and the cooling liquid flow rate adjusting device 40
7, and a mass flow controller 64 that adjusts the flow rate of the cooling liquid based on a signal from the control device 39 is installed in the cooling liquid flow rate adjusting device 40.

The cooling liquid discharge ports 59 are provided on both sides of the cutting position of the semiconductor wafer 41 at the lower end of the blade 33, and open on both sides of the blade 33 from both sides to face the cutting position of the semiconductor wafer 41. Then, the cooling liquid consisting of pure water is discharged. The cooling liquid discharged from the discharge port 59 cools the frictional heat of the blade 33 and also flushes the cutting powder of the semiconductor wafer 41.

The cooling liquid discharge port 56 is the cooling liquid discharge port 5
It is attached above 9 and opens so as to face the cutting blade of the blade 33 and discharges the cooling liquid toward the cutting blade of the blade 33. The cooling liquid discharged from the discharge port 56 removes friction heat of the blade 33.

A cooling liquid supply source (not shown) is connected to the cooling liquid flow rate adjusting device 40, and the cooling liquid is discharged from the discharge ports 56 and 59 through the cooling liquid flow rate adjusting device 40 and the flow path 37. The discharged cooling liquid hits the blade 33 rotating at a high speed in the clockwise direction as seen in FIG. 2 and is scattered in the rotation direction of the blade 33.

The blade 33 is rotated at a high speed by being given a rotational power from a drive source (not shown), and cuts the semiconductor wafer 41 placed on the dicing table 43. Further, the cutting device 54 moves in the front-back direction (see FIG. 1) at a predetermined moving speed.
Left and right) and left and right (perpendicular to the plane of the paper in Figure 1)
It is provided so that it can reciprocate.

Above the dicing table 43 vertically,
An image input device 38 realized by a CCD camera or the like is arranged, and the image input device 38 takes an image of the planar shape of the semiconductor wafer 41, the electrode pattern, and the like. The captured image is input to the control device 39 as an image signal. Dicing conditions such as the rotation speed of the blade 33 and the flow rate of the cooling liquid are input to the control device 39 from the operation unit 55.

The control device 39 outputs a cooling liquid flow rate control signal to the cooling liquid flow rate adjusting device 40 and an operation signal to the cutting device 54 based on the image signal and the dicing condition signal.

Next, the semiconductor wafer 41 is divided into a plurality of semiconductor chips 51 by the dicing apparatus 32 of the present embodiment.
The dicing step will be described with reference to FIGS. In FIG. 3, the semiconductor wafer 41 is placed on the dicing sheet 7
It is a figure which shows the state stuck on top, FIG. 4 is a figure which shows the state when the semiconductor wafer 41 is cut | disconnected in a 1st direction, and FIG. 5 is cut | disconnected in a 2nd direction perpendicular | vertical to a 1st direction. It is a figure which shows the state at the time. 4 and 5, the housing 35 of the cutting device 54 is omitted for convenience of illustration.

In FIGS. 4 and 5, the virtual line 44 is
The virtual line 45 is a straight line that passes through the center of the semiconductor wafer 41 and is parallel to the first direction. The virtual line 45 is a straight line that passes through the center of the semiconductor wafer 41 and is parallel to the second direction that is perpendicular to the first direction.

The imaginary line 65 is a circle that is concentric with the semiconductor wafer 41 and has a diameter of 10 mm, and the blade 33 is moved in the first and second directions up to this circular area that is larger than the semiconductor wafer 41, and the semiconductor wafer is moved. 41 around edge 4
Completely cut to 7. Hereinafter, the area surrounded by the virtual line 65 will be referred to as a cutting work area 78, and the cutting work area 78 will be described.
A region for cutting the semiconductor wafer 41 therein is referred to as a cutting region 79, and an annular region other than the cutting region 79 within the cutting work region 65 for cutting the dicing sheet 42 is referred to as a cutting region 73.

The dimension of the semiconductor wafer 41 is such that the thickness t3 = 3.
The thickness is 00 μm, the diameter D3 is 2 inches, and the thickness t4 of the dicing sheet 42 is 1.0 mm. An adhesive layer is formed on the surface of the dicing sheet 42, and the semiconductor wafer 41 is attached to the center of the adhesive layer of the dicing sheet 42 as shown in FIG. Further, as shown in FIG. 1, the semiconductor wafer 41 is placed on the dicing table 43 such that the top surface of the semiconductor wafer 41 faces the image input device 38. The dicing sheet 42 is vacuum-adsorbed on the dicing table 43, whereby the semiconductor wafer 41
Is fixed on the dicing table 43 so as not to move.

The semiconductor wafer 41 is the dicing table 4
When fixed on the No. 3, the operator inputs the dicing conditions from the operation unit 55 to the control device 39. In this embodiment, the dicing conditions input at this time are as follows: the rotation speed of the blade 33 is 30,000 rpm, the blade height is 0.07 mm,
The dicing interval is 0.20 mm, and the moving speed of the cutting device 54 in the front-rear direction (left-right direction in FIG. 1) is 10 mm / sec. Further, the operator inputs the flow rate condition of the cooling liquid from the operation unit 55 to the control device 39. In the present embodiment, the flow rate condition of the cooling liquid input at this time is that the discharge flow rate of the cooling liquid in the semi-arc shaped flow rate decreasing region 70 on the right side of the imaginary line 45 of the cut region 73 in FIG. When the cutting work area 78 except the area 70 is cut, the discharge flow rate of the cooling liquid is set to 0.8 liter per minute.

Next, the planar shape of the semiconductor wafer 41, the mounting position on the dicing table 3 and the electrode pattern are imaged by the image input device 38 above the dicing table 43. The captured image information is input to the control device 39 as an image signal. When the image signal is input, the control device 39 performs alignment based on the image signal and searches for a plurality of cut lines 74 parallel to the virtual line 44. After that, the control device 39 stores the line to be cut 74 and moves the blade 33 along the line to be cut 74.
Calculates an operation signal of the cutting device 54 for cutting the semiconductor wafer 41 and outputs the operation signal to the cutting device 54 to start the dicing operation.

When this operation signal is input to the cutting device 54, rotational power is given from the drive source to the blade 33,
When viewed from FIG. 1, the rotating shaft 36 rotates in the clockwise direction at a rotation speed of 30,000 rpm when viewed from FIG. When the blade 33 is rotationally driven, the cooling liquid is discharged from the discharge ports 56 and 59.

Referring to FIG. 4, the blade 33 has a virtual line 6
When moved to the position above 5, the cutting device 54 moves downward so that the blade height becomes 0.07 mm on the imaginary line 65, starts cutting the dicing sheet 42, and starts the cutting work.

Next, when the cutting device 54 moves in the direction of the arrow 66, the dicing sheet 42 is cut in the cut region 73, and the blade 33 causes the peripheral edge 47 of the semiconductor wafer 41.
When the temperature reaches, the semiconductor wafer 41 starts to be cut. When the cutting device 54 moves further in the direction of arrow 66, the semiconductor wafer 41 is cut in parallel with the imaginary line 44, and the blade 33 passes over the peripheral edge 47 of the semiconductor wafer 41, the semiconductor wafer 4
1 is completely cut. Further, the blade 33 cuts the dicing sheet 42 until it reaches the imaginary line 65,
When reaching the imaginary line 65, the blade 33 is quickly pulled upward. In this way, the semiconductor wafer 41 is cut by cutting into the notch region 73 having an area larger than that of the semiconductor wafer 41, so that the semiconductor wafer 41 is completely cut along the searched cut line 74. .

After the blade 33 is pulled up,
The cutting device 54 slides in the left-right direction (in a direction parallel to the imaginary line 45 in FIG. 4) by 0.2 mm, and when it moves above the imaginary line 65, it moves downward so that the blade height becomes 0.07 mm. Start cutting the dicing sheet 42 from above the imaginary line 65.

Further, the blade 33 is moved in the direction of the arrow 67 to completely cut the semiconductor wafer 41 in parallel with the imaginary line 44 in the same manner as described above. Be raised to. Thereafter, similarly to the above, the blade 33 is slid and displaced in one of the left and right directions (the direction parallel to the imaginary line 45 in FIG. 4) at intervals of 0.2 mm, and is moved in the direction of arrow 66 parallel to the imaginary line 44 to move the semiconductor wafer Cut 41.

By sequentially repeating the above operation,
The semiconductor wafer 41 is cut in the left-right direction in parallel with the imaginary line 44 at intervals of 0.2 mm. That is, all of the plurality of cut lines 74 parallel to the virtual line 44 searched in advance are cut.

During the cutting operation for cutting the above-mentioned semiconductor wafer 41 a plurality of times in parallel with the imaginary line 44, the discharge ports 56, 59 are provided.
The flow rate of the cooling liquid discharged from is kept constant at 0.8 liters per minute.

When all the cutting of the cut line 74 parallel to the imaginary line 44 of the semiconductor wafer 41 is completed, the controller 39
Outputs to the cutting device 54 an instruction to return the cutting device 54 to the predetermined cutting start position, and the cutting device 54 returns to the predetermined cutting start position in response to this. After the cutting device 54 has returned to the predetermined start position, the dicing table 43 moves to the central axis 71.
Rotate 90 ° counterclockwise as viewed from FIG.
After the dicing table 43 is rotated by 90 °, the image input device 38 again images the planar shape and the electrode pattern of the semiconductor wafer 41, and outputs the imaged image information to the control device 39 as an image signal.

When the image signal is input, the control device 39
Performs alignment based on this image signal, and
Direction virtual line 44 that is the second direction perpendicular to virtual line 44 that is the direction
A plurality of cut lines 75 parallel to 5 are searched. The control device 39 stores the plurality of cut lines 75, and operates the cutting device 54 for the blade 33 to cut the semiconductor wafer 41 along the cut lines 75 based on the cut lines 75. A signal is calculated, this operation signal is output to the cutting device 54, and the dicing operation is started again.

After that, the cutting device 54 is reciprocated in the directions of the arrows 66 and 67 along the line to be cut 75 in the same manner as described above, and all the lines to be cut 75 are cut by the blade 33.

In this way, the semiconductor wafer 41 is divided into a plurality of semiconductor chips 51, and each of the divided semiconductor chips 51 has a length of 0.17 mm and a width of 0.1.
It will be 7 mm.

In the controller 39, the blade 33 has a ring-shaped cut area 73 around the semiconductor wafer 41.
Only when the semicircular arc-shaped region 70 shown by the diagonal line on the right side of the imaginary line 44 is cut, an instruction to set the flow rate of the coolant discharged from the discharge ports 56 and 59 to 0.5 liters per minute is given. Output to. Based on this command, the cooling liquid flow rate adjusting device 40 changes the discharge flow rate from 0.8 liters per minute to 0.5 liters per minute.

That is, the control device 39 controls the cutting device 54.
When the blade 33 reaches the peripheral edge 47 of the semiconductor wafer 41 while moving in parallel with the imaginary line 45 in the direction of the arrow 67 and cutting the semiconductor wafer 41, the blades 33 reach 0.8 mm per minute from the discharge ports 56 and 59. It outputs a command to change the flow rate of the cooling liquid discharged in liters to 0.5 liters per minute.

In this way, the semicircular arc-shaped flow reduction region 7
When 0 is cut, the discharge flow rate of the cooling liquid is reduced to 0.5 liters per minute, so that the flow rate of the cooling liquid discharged in the direction of arrow 69 also decreases accordingly. That is, the flow rate of the cooling liquid sprayed from the right side to the wall surface of the right edge of the semiconductor wafer 41 in FIG. 5 is reduced as compared with the conventional technique, and the cooling liquid does not vigorously hit the side wall of the semiconductor wafer 41.

When the cooling liquid vigorously hits the wall surface of the right peripheral edge of the semiconductor wafer 41, the semiconductor chips 20 existing in the range surrounded by the virtual line 25 in FIG.
However, in the semiconductor wafer dicing method of the present invention, the momentum of the cooling liquid at the peripheral edge is reduced, so the semiconductor chip 51 at the right peripheral edge portion in FIG. 5 is not separated and the semiconductor chip 51 is prevented from flying. , The yield is improved.

Further, in the prior art, the semiconductor chip 20 separated by the cooling liquid sprayed on the side wall of the peripheral edge of the semiconductor wafer 6 flies to the central portion of the semiconductor wafer 6,
Semiconductor chip 20 formed at the center of semiconductor wafer 6
At this time, there was a problem that the semiconductor chip 20 in the central portion was cracked or chipped. However, in the semiconductor wafer dicing method of the present invention, since the semiconductor chip 51 is prevented from jumping, the semiconductor chip 51 is cracked or chipped. Is prevented and the yield is improved.

When the semiconductor wafer 41 is cut,
The flow rate of the cooling liquid discharged from the discharge ports 56 and 59 is 0.8 liters / minute, as in the conventional technique.
During the cutting of the semiconductor wafer 41 in which the frictional heat of 3 increases,
Since the discharge flow rate of the cooling liquid is not reduced, the blade 33 is sufficiently cooled, and the cutting powder of the semiconductor wafer 41 is reliably removed.

Further, since the control device 39 controls the time for reducing the discharge flow rate of the cooling liquid to the minimum only when cutting the flow rate reduction area 70, deterioration of the blade 33 due to frictional heat is minimized. However, semiconductor chip 51
Can be prevented and the yield can be improved.

Further, since the semiconductor chip 51 is prevented from jumping, it is possible to prevent the blown semiconductor chip 51 from hitting the blade 33 and cracking or chipping the blade 33.

When the semiconductor wafer 41 is diced using the semiconductor wafer dicing apparatus 32 of this embodiment,
It has been confirmed by the applicant of the present application that the yield is improved as shown in Table 1 without deterioration of the blade 33.

[0068]

[Table 1]

In the prior art, the yield reduction due to semiconductor chip jump was 5%, whereas when the semiconductor wafer dicing method of this embodiment is used, the yield reduction is up to 0%. improves.

In the prior art, the yield reduction due to the cracking of the semiconductor chip was 5%, whereas
When the semiconductor wafer dicing method of the present embodiment is used, the yield reduction amount is improved to 0%.

In the prior art, the yield reduction due to chipping of the semiconductor chip was 10%, whereas the semiconductor wafer dicing method of this embodiment reduced the yield to 1%. Decrease.

As a whole, in the prior art, the total yield was only 80%, whereas when the semiconductor wafer dicing method of the present invention was used, the total yield was 9%.
It can be improved up to 9%, and production efficiency and manufacturing cost are dramatically improved.

Further, in the semiconductor wafer dicing method of the present invention, the semiconductor chips 51 can be prevented from jumping without using a dicing sheet having a strong adhesive force, so that the dicing sheet 42 having an optimal adhesive force can be used. Almost no stress is applied to the semiconductor chip 51 after division, and the semiconductor chip 51 is not cracked or chipped.
Further, workability in the steps after dicing does not decrease.

A semiconductor wafer dicing method and a semiconductor wafer dicing apparatus according to the present invention include a semiconductor chip 51.
The size of the top surface is 0.20 mm or less in height and 0.20 m in width.
It can be carried out particularly suitably when divided into squares of m or less.

In the semiconductor wafer dicing method and the semiconductor wafer dicing apparatus according to the present invention, when the flow rate decreasing region 70 shown in FIG. 5 is cut, the discharge rate of the cooling liquid is 0.4 to 0.6 liters per minute. Then, when cutting the cutting work area 79 excluding the area 70 where the flow rate is reduced, the discharge flow rate of the cooling liquid is set to 0.7 liter to 0.9 liter per minute, which is particularly preferable.

The semiconductor wafer dicing method and the semiconductor wafer dicing apparatus according to the present invention have a diameter D3 = 2.
Not only the semiconductor wafer 41 of the inch is cut, but the diameter is 3 inch, 4 inch, 5 inch, 6 inc.
h, 8 inch and 12 inch semiconductor wafers 41
The cutting operation can also be suitably performed.

A semiconductor wafer dicing method and a semiconductor wafer dicing apparatus according to the present invention are a GaP wafer,
GaAsP wafer, GaAs wafer and GaAlAs
The present invention can also be suitably applied to compound semiconductor wafers such as wafers and elemental semiconductors such as silicon and germanium.

[0078]

As described above, according to the present invention, the semiconductor wafer to be cut is attached on the dicing sheet and fixed on the dicing table. The cutting device has a rotating blade, and the rotating blade cuts the semiconductor wafer on the dicing sheet in parallel to a predetermined first direction and a second direction perpendicular to the first direction until the dicing sheet is cut a plurality of times. It is cut and divided into a plurality of semiconductor chips.

At the cutting position of the semiconductor wafer, the cooling liquid is discharged from the cooling liquid discharging device to wash away the cutting powder of the semiconductor wafer and cool the blade. The cooling liquid discharge device and the cutting device are controlled by the control device.
The cooling liquid discharge device has a cooling liquid flow rate adjusting device for adjusting the discharge flow amount of the cooling liquid, and the control device changes the discharge flow amount of the cooling liquid during the cutting operation.

When the semiconductor chip is peeled off from the dicing sheet and the peripheral portion of the semiconductor wafer is liable to fly, the control device reduces the discharge flow rate of the cooling liquid. This reduces the amount of cooling liquid that hits the semiconductor chips on the periphery of the semiconductor wafer, so that the semiconductor chips are less likely to be peeled off from the dicing sheet, the semiconductor chips are prevented from flying, and the yield is improved. Further, when cutting the inside of the semiconductor wafer, the discharge flow rate of the cooling liquid is still high, so that the cooling effect of the blade 2 is not reduced and deterioration is suppressed. In addition, it is possible to use a dicing sheet with the best adhesive strength, you do not have to use a strong adhesive dicing sheet, and there is no large stress on the semiconductor chip, so you can prevent cracking or chipping of the semiconductor chip You can In addition, workability in the steps after the dicing step is also improved.

Further, according to the present invention, since the control device reduces the flow rate of the cooling liquid when the blade reaches the periphery of the semiconductor wafer, the time during which the cooling effect of the blade is reduced is minimized and the deterioration of the blade is prevented. It can be minimized, semiconductor chips can be prevented from jumping, and the yield can be improved.

Furthermore, according to the present invention, the image recognition device recognizes the shape of the semiconductor wafer, and the control device adjusts the flow rate of the cooling liquid based on the recognized shape of the semiconductor wafer. When cutting the peripheral part, the discharge flow rate is surely reduced, and when the blade is off the peripheral part, the discharge flow rate is rapidly increased, so that deterioration of the blade can be minimized and the semiconductor chip Flying is prevented and the yield is improved.

Further, according to the present invention, the top surface of the divided semiconductor chip has a length of 0.20 mm or less and a width of 0.20 mm.
In the case of the following quadrangle, the contact area between the dicing sheet and the semiconductor chip becomes extremely small as described above,
In the prior art, semiconductor chips were easy to fly. According to the present invention, even in such a case, the semiconductor chips are reliably prevented from jumping, and the yield is greatly improved.

Further, according to the present invention, the control device sets the discharge flow rate of the cooling liquid to 0.4 liters per minute or more and 0.6 liters per minute or less when cutting the peripheral portion of the semiconductor wafer, When cutting, the discharge flow rate of the cooling liquid is set to 0.7 liter or more and 0.9 liter or less per minute.

When the semiconductor wafer is cut by such a method, the semiconductor chips are hardly jumped, cracked or chipped, the yield is dramatically improved, and the reduction of the blade life is suppressed.

Further, according to the present invention, the semiconductor wafer to be cut is attached on the dicing sheet and fixed on the dicing table. The cutting device has a rotating blade, and this rotating blade predetermines a semiconductor wafer on a dicing sheet in a first direction and in the first direction.
The dicing sheet is cut parallel to the second direction perpendicular to the direction and cut a plurality of times to divide into a plurality of semiconductor chips.

The cooling liquid discharging device and the cutting device are controlled by the control device. The cooling liquid discharge device has a cooling liquid flow rate adjusting device for adjusting the discharge flow amount of the cooling liquid, and the control device changes the discharge flow amount of the cooling liquid during the cutting operation.

At the cutting position of the semiconductor wafer, the cooling liquid is discharged from the cooling liquid discharging device to wash away the cutting powder of the semiconductor wafer and cool the frictional heat of the blade.
The cooling liquid discharge device has a cooling liquid flow rate adjusting device, and the control device is changed by the cooling liquid flow rate adjusting device during the cutting operation.

For example, when the semiconductor chip is peeled off from the dicing sheet and the peripheral portion of the semiconductor wafer is liable to fly, the controller reduces the discharge flow rate of the cooling liquid. As a result, the semiconductor chips are less likely to peel off from the dicing sheet until the amount of the cooling liquid that hits the semiconductor chips around the periphery of the semiconductor wafer is reduced, the semiconductor chips are prevented from flying, and the yield is improved.
Further, when the inside of the semiconductor wafer is cut, the discharge flow rate of the cooling liquid remains high, so that the cooling effect of the blade 2 is not reduced and deterioration is suppressed.

[Brief description of drawings]

FIG. 1 is a dicing apparatus 3 according to an embodiment of the present invention.
2 is a schematic view of FIG.

FIG. 2 is an enlarged view of a cutting device 54.

FIG. 3 is a diagram in which a semiconductor wafer 41 is attached onto a dicing sheet 42.

FIG. 4 is a diagram showing a state when the semiconductor wafer 41 is cut parallel to the first direction.

FIG. 5 is a diagram showing a state when the semiconductor wafer 41 is cut parallel to a second direction perpendicular to the first direction.

FIG. 6 is a diagram showing a conventional semiconductor wafer dicing method.

7 is a diagram showing a region 25 in which the semiconductor chip 20 is peeled off by the cooling liquid discharged in the direction of arrow 24. FIG.

[Explanation of symbols]

32 Dicing equipment 33 blade 38 Image Input Device 39 Control device 40 Coolant flow rate adjusting device 41 Semiconductor wafer 42 dicing sheet 51 semiconductor chips 54 cutting device 56, 59 outlet

Claims (6)

(57) [Claims] 1. A dicing table for fixing a dicing sheet having a semiconductor wafer attached thereto, a cutting device having a blade for rotating and cutting the semiconductor wafer, and a cooling device for discharging a cooling liquid toward a cutting position of the semiconductor wafer. A liquid ejecting device and a controller for controlling the cutting device and the cooling liquid ejecting device are provided, and the semiconductor wafer attached on the dicing sheet is bladed with a first direction and a second direction perpendicular to the first direction. In a method for dicing a semiconductor wafer in which a dicing sheet is cut and cut a plurality of times in parallel with each other in each direction to divide into a plurality of semiconductor chips, the cooling liquid discharge device adjusts a cooling liquid flow rate adjustment for adjusting a discharge flow rate of the cooling liquid. The control device has a device for discharging a cooling liquid when performing a cutting operation on the peripheral portion of the semiconductor wafer. Dicing a semiconductor wafer, wherein a reduced. 2. The control device reduces the flow rate of the cooling liquid when the blade reaches the periphery of the semiconductor wafer when cutting the semiconductor wafer in parallel with the second direction.
The method for dicing a semiconductor wafer according to claim 1, wherein the cooling liquid flow rate adjusting device is controlled. 3. An image recognition device for recognizing the shape of a semiconductor wafer, wherein the controller adjusts the flow rate of the cooling liquid based on the recognized shape of the semiconductor wafer. A method for dicing a semiconductor wafer according to claim 1. 4. The size of the top surface of the divided semiconductor chip is a quadrangle having a length of 0.20 mm or less and a width of 0.20 mm or less.
Dicing method described in. 5. The controller controls the discharge flow rate of the cooling liquid to be 0.4 per minute when the peripheral portion of the semiconductor wafer is cut.
A liter or more and 0.6 liter or less, and when the inside of the semiconductor wafer is cut, the discharge flow rate of the cooling liquid is 0.7 liter or more and 0.9 liter or less per minute. The dicing method according to any one of claims. 6. A dicing table for fixing a dicing sheet having a semiconductor wafer attached thereto, a cutting device having a blade for rotating to cut the semiconductor wafer, and a cooling device for discharging a cooling liquid toward a cutting position of the semiconductor wafer. A liquid ejecting device and a controller for controlling the cutting device and the cooling liquid ejecting device are provided, and the semiconductor wafer attached on the dicing sheet is bladed with a first direction and a second direction perpendicular to the first direction. In a method for dicing a semiconductor wafer in which a dicing sheet is cut and cut a plurality of times in parallel with each other in each direction to divide into a plurality of semiconductor chips, the cooling liquid discharge device adjusts a cooling liquid flow rate adjustment for adjusting a discharge flow rate of the cooling liquid. The control device has a device for discharging a cooling liquid when performing a cutting operation on the peripheral portion of the semiconductor wafer. A semiconductor wafer dicing apparatus characterized by a reduced.