JP2002075919A - Dicing method of semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the peeling of a semiconductor chip 35 and an end piece 36 near a periphery section 33 when dicing a semiconductor wafer 23 attached onto a wafer sheet 22 without increasing the adhesive force of the wafer sheet 22. SOLUTION: The periphery section 33 of the semiconductor wafer 23 is partially diced in a thickness direction from the surface for setting remaining thickness d2 to 10 to 100 μm. At an inner semiconductor chip formation section 34 surrounded by the periphery section 33, notching is made over the entire thickness direction for cutting. At the periphery section 33, the movement speed of a blade 29 is set faster than that at the semiconductor chip formation section 34 (v2<v1<v3), and the flow rate of cutting water is decreased at the periphery section 33 at a downstream side in a movement direction (q1=q2>q3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor wafer,
The present invention relates to a method of dicing a semiconductor wafer to a desired semiconductor chip size.

[0002]

2. Description of the Related Art Conventionally, in manufacturing a semiconductor device, a diffusion step of forming a circuit of a semiconductor element on the surface of a semiconductor wafer has been performed, and then, a step of measuring the electrical characteristics of the semiconductor wafer has been performed, and further thereafter, Is put into the assembly process. In the assembling process, a dicing process of a semiconductor wafer is performed.

FIG. 6 is a sectional view showing a dicing process according to the first prior art. The back surface (the lower surface in FIG. 6) of the semiconductor wafer 2 is adhered to the adhesive wafer sheet 1,
In this state, the dicing blade 3 is moved as shown by the arrow 5 while being rotationally driven as shown by the arrow 4, whereby the semiconductor wafer 2 is cut in the entire thickness direction, and the dicing blade 3 is cut. Is cut to an intermediate area 6 in the thickness direction of the wafer sheet 1. As shown in FIG. 6, the dicing step of cutting the entire thickness of the semiconductor wafer 2 by the blade 3 is called a full dicing method. The state where the blade 3 has moved in the moving direction 5 is indicated by reference numeral 3a. A nozzle 7 for injecting cutting water is attached downstream of the moving direction 5 of the blade 3 to cool the semiconductor wafer 2 by the blade 3 and to remove cutting chips from the surface of the semiconductor wafer 2. I do.

FIG. 7 is a plan view of the semiconductor wafer 2 according to the first prior art shown in FIG. The moving direction 5 of the blade 3 is along dicing lines 8 and 9 which are perpendicular to each other. By such a dicing process, a large number of rectangular semiconductor chips 10 shown by hatching in FIG. 7 are divided.

In the first prior art shown in FIGS. 6 and 7, the cutting depth of the blade 3 along the dicing lines 8 and 9, the speed in the moving direction 5, and the flow rate of the cutting water from the nozzle 7 are respectively It is kept at a constant value. Blade 3
Is rotating at a high speed, and the cutting water from the nozzle 7 is jetted vigorously and flows on the surface of the semiconductor wafer 2. The outer peripheral portion 11 of the semiconductor wafer 2 is chamfered from both the front and back surfaces to form an outwardly convex curved shape. Therefore, on the downstream side along the moving direction 5 of the dicing lines 8 and 9, the semiconductor chips 10 and the end pieces 12 outside the outer peripheral portion 11 of the semiconductor wafer 2 are rotated by the blade 3 and cut from the nozzle 7. By jetting water,
It peels off from the wafer sheet 1 and scatters. The scattered semiconductor chip 10 and the end piece 12 collide with the blade 3, causing the blade to chip and break. The semiconductor wafer 2 is scratched by damage such as chipping or cracking of the blade 3, and a dicing defect occurs.
This results in defective products. Damage to the blade makes subsequent dicing steps impossible.

FIG. 8 is a simplified cross-sectional view of another second prior art which solves the problem of the full dice system shown in FIGS. 6 and 7. Parts corresponding to the prior art in FIGS. 6 and 7 are denoted by the same reference numerals. In the second prior art, there is a thickness d1 which is partially diced from the surface of the semiconductor wafer 2 in the thickness direction and is not cut. Such a dicing step is carried out when the uncut thickness d1 is about several tens.
μm, which is called a semi-full die method, and the thickness d1 is 10
It is referred to as a half-die method in which the number is 10 μm. The prior art shown in FIG. 8 has an advantage that the semiconductor chip 10 and the end piece 12 (see FIG. 7) are kept adhered to the wafer sheet 1 during dicing by the blade 3 and are hardly peeled off.

A new problem of the second prior art shown in FIG. 8 is that the back surface of the semiconductor chip 10 is continuous at the portion having the above-mentioned thickness d1, so that the break process executed after the dicing process in the assembly process. , Each semiconductor chip 10
Needs to be cut along the dicing lines 8 and 9 to be divided. At this time, the thickness d1 of the semiconductor chip 10 is
Cleavage near the part. Therefore, the semiconductor chip 1
0 electrical characteristics and reliability are reduced.

A third prior art which solves the problems of the prior arts shown in FIGS. 6 to 8 is disclosed in Japanese Patent Laid-Open No. 5-904.
06.

FIG. 9 is a simplified plan view for explaining the third prior art. Corresponding parts of the first and second prior art have the same reference numerals. Semiconductor wafer 2
The semiconductor chip 10 and the end piece 12 are obtained by cutting along a first cut line 15 and a second cut line 16 perpendicular to the first cut line 15 with a blade. In this prior art, the first
A first cut line having a dicing start point outside the peripheral portion of the semiconductor wafer among the cut lines 15 of the above, and a second cut line having a dicing start point within the peripheral portion of the semiconductor wafer 2 are provided alternately. The same is true for the other cut line 16 perpendicular to the one cut line 15.

[0010] Even in the third prior art, when the semiconductor chip 10 is relatively small or the end piece 12 is relatively small, peeling and scattering from the wafer sheet 1 during dicing cannot be suppressed. Also, this third
In the prior art, there is an end piece having a relatively large shape, and thus, in a subsequent die bonding step, for example, when the wafer sheet 1 is pulled and expanded to increase the distance between the semiconductor chips 10, the semiconductor chips 10 are separated from each other. There is also a problem that the intervals become non-uniform.

Although it is conceivable to increase the adhesive force of the wafer sheet 1 in order to prevent the semiconductor chip 10 and the end piece 12 from peeling off and scattering from the wafer sheet 1, such a large adhesive force causes the semiconductor chip 10 When the semiconductor chip 10 is removed from the wafer sheet 1 and picked up, the semiconductor chip 10 must be pulled and separated with a large force, which results in damage to the semiconductor chip 10. In addition, in a configuration using an ultraviolet curable resin as such an adhesive having a large adhesive strength, the cost increases and the cost is inferior to the cost reduction.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent the semiconductor chips and end pieces from peeling off and scattering from the wafer sheet at the time of dicing without increasing the adhesive force with the wafer sheet. Dicing method of a semiconductor wafer so as not to be damaged,
An object of the present invention is to provide a semiconductor wafer structure and a semiconductor wafer dicing apparatus.

[0013]

According to the present invention, in a state where the back surface of a semiconductor wafer is adhered to a wafer sheet, the peripheral portion of the semiconductor wafer is partially diced in the thickness direction from the front surface of the semiconductor wafer. A dicing method for a semiconductor wafer, characterized in that a semiconductor chip forming portion surrounded by a peripheral portion is cut and diced in the entire thickness direction.

According to the present invention, the peripheral portion of the semiconductor wafer is partially cut in the thickness direction by using a dicing blade that is rotated while the back surface of the semiconductor wafer is adhered to the wafer sheet. A part in the thickness direction on the wafer sheet side remains without being cut, and is thus diced by a semi-full dicing method or a half dicing method. In the semiconductor chip forming portion inside the peripheral portion surrounded by the peripheral portion, the semiconductor chip is cut in the entire thickness direction and diced by a full dicing method. Therefore, the semiconductor chip 35 and the end piece 36 near the peripheral portion of the semiconductor wafer
However, it does not peel off from the wafer sheet at the time of dicing with a blade, thereby preventing scattering. Therefore, the semiconductor chip or the end piece colliding with the blade is prevented from being damaged due to chipping or cracking of the blade, the life of the blade can be extended, and the semiconductor wafer is damaged by such scattering. However, productivity, workability and yield are improved.

Further, the end piece near the peripheral portion of the semiconductor wafer is partially cut in the thickness direction as described above, so that the end piece can be folded and cut into a relatively small shape. Therefore, as described in connection with the prior art in FIG. 10, when the wafer sheet is enlarged in the die bonding step following the dicing step, the intervals between the semiconductor chips can be made substantially uniform, and the operation can be improved. Can be.

In the peripheral portion, the circuit of the semiconductor element may not be formed, but such a circuit may be formed, and in the semiconductor chip forming section, the circuit of the semiconductor element is formed. A semiconductor chip may be included, and an end piece without such a circuit may be present. The wafer sheet has an adhesive force capable of holding the diced semiconductor chips of the semiconductor wafer and peeling the semiconductor chips without damaging the semiconductor chips, for example, 2.94 N / 25 mm (300 gf / 25).
mm). The outer peripheral portion, which is outward of the peripheral portion of the semiconductor wafer, is chamfered from both front and back surfaces, has a curved or inclined shape that is convex outward, and even with such a configuration, the present invention provides For example, when dicing the peripheral portion of the semiconductor wafer, there is no possibility that the semiconductor chips and the end pieces are separated from the wafer sheet.

Further, the present invention is characterized in that dicing is performed so that the remaining thickness of the peripheral portion is 10 to 100 μm.

According to the present invention, the thickness d2 of the peripheral portion of the semiconductor wafer which is left uncut is selected to be 10 to 100 μm, and dicing is performed by a so-called semi-full dicing method. This makes it easy to divide the semiconductor chip and the end piece at the peripheral portion of the semiconductor wafer, and can suppress the occurrence of chipping and cracking on the back surface side of the semiconductor wafer in the remaining thickness d2.

If the remaining thickness d2 is less than 10 μm, there is a risk that the peripheral end pieces may be peeled off from the wafer sheet during dicing, and it is necessary to increase the adhesive force. When the remaining thickness d2 exceeds 100 μm,
When the semiconductor chip and the end piece near the periphery are separated,
Chipping or cracking on the back surface side of the semiconductor wafer near the remaining thickness tends to occur, and the yield deteriorates.

Further, according to the present invention, the rotational speed of the dicing blade is maintained at a predetermined constant value, and the moving speed of the dicing blade along the dicing line is higher at the peripheral portion on the upstream side in the moving direction than at the semiconductor chip forming portion. As
The speed is higher at the peripheral portion on the downstream side in the moving direction than at the peripheral portion on the upstream side in the moving direction.

According to the present invention, while keeping the rotation speed of the blade at a constant value, the speed of the dicing blade in the direction of movement along the dicing line is reduced by a load that cuts over the entire thickness in a peripheral portion where cutting is small and the load is small. The speed is set to be higher than that of the chip forming portion having a larger value (v1> v2 and v3> v2 in FIG. 3B described later), thereby shortening the dicing time and improving the productivity.

Further, according to the present invention, the moving speed of the blade is set higher (v1 <v3) in the peripheral portion on the downstream side in the moving direction of the blade than in the peripheral portion on the upstream side, whereby cutting water is formed on the semiconductor wafer. In this configuration, the semiconductor chips and the end pieces near the peripheral portion on the downstream side in the moving direction are reliably prevented from peeling off from the wafer sheet due to the adverse effect of the cutting water.

The present invention is also directed to a method for cutting water at a cutting portion of a semiconductor wafer by a dicing blade so as to reduce the flow rate of the cutting water when cutting a semiconductor chip forming portion and then cutting a peripheral portion. Features.

According to the present invention, when dicing a semiconductor wafer by moving the blade, the flow rate of the cutting water is reduced at the peripheral portion downstream of the semiconductor chip forming portion in the moving direction of the blade (see FIG. ), Q2>
q3). This ensures that the semiconductor chip and the end piece near the peripheral portion on the downstream side in the moving direction are prevented from being separated due to cutting water jetting.

The cutting water is used to cool the semiconductor wafer by preventing the temperature of the semiconductor wafer from rising due to the cutting, to reduce the load on the blade for reducing the cutting resistance of the blade, to prevent the cutting blade of the blade from being clogged, It functions to wipe off chips generated by cutting the wafer from the surface of the semiconductor wafer.

Further, according to the present invention, a back surface of a semiconductor wafer is attached to a wafer sheet, and a cut portion is formed along a plurality of dicing lines. The semiconductor wafer structure has a thickness of 10 to 100 μm, and is cut and cut in the entire thickness direction in a semiconductor chip forming portion surrounded by a peripheral portion. .

In the semiconductor wafer structure of the present invention, the peripheral portion of the semiconductor wafer attached to the wafer sheet is partially cut from the surface in the thickness direction, leaving a thickness d2 of 10 to 100 μm. Since the semiconductor chip forming portion inside the portion is cut in the entire thickness direction, the peripheral end piece can be divided along the dicing line to make the end piece relatively small. Thereby, in a state following the dicing step, for example, in a die bonding step, in a state where the wafer sheet is enlarged, the intervals between the semiconductor chips can be made substantially uniform, and the workability can be improved.
The semiconductor chips of the semiconductor wafer structure and the end pieces of the peripheral portion do not undesirably peel off from the wafer sheet, and the semiconductor chips are relatively separated from the wafer sheet so that the semiconductor chips are not damaged. It is easy to peel off from the wafer sheet with a small tensile force.

According to the present invention, there is provided a dicing table on which a wafer sheet to which a back surface of a semiconductor wafer is adhered is placed, a dicing blade disposed above the table and driven to rotate, and a table and a dicing blade. A moving displacement unit that translates parallel to the mounting surface of the table, and moves close to and away from the mounting surface in a vertical direction, and partially dicing the peripheral portion of the semiconductor wafer on the table from the surface of the semiconductor wafer in the thickness direction; A semiconductor wafer dicing apparatus characterized by including a control means for controlling a moving and displacing means such that a semiconductor chip forming portion surrounded by a peripheral portion cuts and dices all over the thickness direction.

According to the present invention, the dicing operation of the semiconductor wafer can be automatically continued without peeling off the semiconductor chips and end pieces near the peripheral portion of the semiconductor wafer.

[0030]

FIG. 1 is a simplified sectional view showing the structure of an embodiment of the present invention. In a semiconductor wafer dicing apparatus 21, a wafer sheet 22 provided with an adhesive at least on the upper surface of FIG.
The back surface 24 of the semiconductor wafer 23 is adhered on the semiconductor wafer 2 to form a semiconductor wafer structure 25. This semiconductor wafer structure 2
5 is fixed to a table 26 having a horizontal mounting surface on the dicing device 21. The outer peripheral portion 41 of the peripheral portion 33 of the semiconductor wafer 23 is chamfered from both the rear surface 24 and the front surface 42 thereof, and has a curved or inclined shape convex outward. The table 26 is configured to be angularly displaceable by 90 degrees around a vertical axis 27. Above the table 26, a blade 29 having a horizontal rotation axis 28 parallel to the mounting surface of the table 26 is driven to rotate at a high speed in a rotation direction 30. At the time of dicing, the blade 29 is reciprocated in the movement direction 31 parallel to the mounting surface of the table 26 and in the opposite direction. During this movement, the blade 29 performs a dicing operation and also moves the semiconductor wafer in the z direction, which is the vertical direction in FIG. 23 is driven so as to be able to approach and leave.
The blade 29 is driven to be displaced in the z direction which is the thickness direction of the semiconductor wafer 23 perpendicular to the xy plane (the vertical direction in FIG. 1 and the vertical direction in FIG. 2A).

FIG. 2 is a diagram for explaining the operation of dicing the semiconductor wafer 23 by the blade 29. FIG. 2A is a plan view of the semiconductor wafer 23.
The semiconductor wafer 23 includes a peripheral portion 33 that is an annular region,
And a semiconductor chip forming portion 34 inside the peripheral portion 33 surrounded by the peripheral portion 33. In order to clarify each region of the peripheral portion 33 and the semiconductor chip forming portion 34,
In FIG. 2A, the hatching is shown. The semiconductor chip forming section 34 includes a semiconductor chip 35 in which a semiconductor element circuit is formed by a diffusion process. Peripheral part 3
3 and further, the semiconductor chip forming portion 34 includes an end piece 36 on which no semiconductor circuit is formed. A semiconductor chip on which a semiconductor circuit is formed may also exist in the peripheral portion 33.

The blade 29 performs a dicing operation by cutting along the plurality of first dicing lines 37 in the x direction 31 which is the left-right direction in FIG. These first dicing lines 37 are formed at predetermined intervals in the y direction. After a plurality of dicing operations are performed on the semiconductor wafer 23 along the dicing line 37, the table 26 is angularly displaced by 90 degrees around the axis 27, and is moved to a second dicing line 38 extending perpendicular to the first dicing line 37. A dicing operation for cutting along is performed. First and second dicing lines 37, 38
Start from outside the peripheral portion 33 of the semiconductor chip 23, and the first and second dicing lines 37, 3
8 ends outside the movement direction 31.

FIG. 2 (2) shows that the semiconductor wafer is
9 is a diagram showing a moving speed of a blade 29 in a moving direction 31 along one dicing line 37a among a plurality of first dicing lines 37 when dicing is performed at 9; FIG. The blade 29 is driven at a constant rotational speed about a rotation axis 28 shown in FIG.
This is a direction that enters the semiconductor wafer 23 on the downstream side (the right side in FIG. 1) of the moving direction 31.

A nozzle 43 is disposed downstream (to the right in FIG. 1) in the moving direction 31 of the blade 29.
At the same time, they move along dicing lines 37 and 38. From the nozzle 43, cutting water is injected. This cutting water is ejected from the nozzle 43 on the upstream side of the cutting position of the semiconductor wafer 23 by the blade 29.

FIG. 2C is a diagram showing the flow rate of cutting water injected from the nozzle 43 when the blade 29 moves in the moving direction 31 along the dicing line 37a. The cutting water suppresses the temperature rise during cutting of the semiconductor wafer 23 and cools it, reduces the cutting resistance of the blade 29, further prevents clogging of the cutting blade of the blade 29, and moves cutting chips of the semiconductor wafer 23. Functions such as wiping on the downstream side in the direction 31 are performed.

When the semiconductor wafer 23 is diced by the blade 29 along, for example, one first blade line 37a, the lower end of the blade 29 in FIG. ~ 5
Displaced as indicated by 0. These lowermost positions 46-50 of the blade 29 indicate the bottom of the cutting groove formed by the blade 29, and in the following description, reference numerals 46-50 may be referred to as the bottom of the cutting groove.

At the peripheral portion 33 of the semiconductor wafer 23, the blade 29 is partially cut from the surface 42 of the semiconductor wafer 23 in the thickness direction (vertical direction in FIG. 1) and diced. Exist in the thickness direction (upper in FIG. 1) than the back surface 24 of the semiconductor wafer 23. In the semiconductor chip forming section 34 of the semiconductor wafer 23,
The semiconductor wafer 23 is cut into the entire bottom in the thickness direction and cut and diced into the bottom 48 of the cutting groove halfway in the thickness direction of the wafer sheet 22. In a region of the peripheral portion 33 near the semiconductor chip forming portion 34, the bottom 47 of the cutting groove is inclined so as to become deeper toward the downstream side in the moving direction 31 of the blade 29. After the cutting of the semiconductor chip forming portion 34, in the peripheral portion 33 on the downstream side in the moving direction 31, the bottom 49 of the cutting groove becomes shallower toward the downstream side in the moving direction 31, and then in the same thickness direction as the aforementioned bottom 46. The bottom 50 is partially cut to form the bottom 50. Thus, similarly to the first dicing line 37a, the other first dicing line 37 and second dicing line 3
8 is also formed.

FIG. 3 is a sectional view taken along the line III-I of FIG.
It is a vertical sectional view seen from II. In the peripheral portion 33 of the semiconductor wafer 23, the bottom 46 of the cutting groove is
Is left uncut from the back surface 24 by a thickness d2. This thickness d2 is selected from 10 to 100 μm as described above.

FIG. 4 is a block diagram showing an electrical configuration of the semiconductor wafer dicing apparatus 21 according to the embodiment of the present invention shown in FIG. A processing circuit 52 realized by a microcomputer or the like is connected to a rotation driving means 53 for driving the blade 29 to rotate about the axis 28.
Moving means 54 that moves in the x and y directions of (1)
In addition, height displacement means 55 for displacing the blade 29 in the z direction in FIG. 2A and each displacement means 56 for angularly displacing the table 26 around the vertical axis 27 are connected. Further, a flow control valve 57 for controlling the flow rate of cutting water supplied to the nozzle 43 is connected to the processing circuit 52.

FIG. 5 is a flowchart for explaining the operation of the processing circuit 52 shown in FIG. When dicing the semiconductor wafer 23, the first dicing line 3
The dicing operation is performed along one of the seven dicing lines 37a. The process proceeds from step s1 to step s2, and it is determined whether or not the region to be cut by the blade 29 is the peripheral portion 33 of the semiconductor wafer 23 by a detecting unit such as a position detecting mechanism. Blade 29
2 (2) in which cutting of the peripheral portion 33 should be started
In the next step s3, when the position is the position p1 shown in FIG. That is, the bottom 46 of the cut groove is formed on the back surface 24 of the semiconductor chip 23.
The position in the z-direction is set by the height displacing means 55 so that the thickness d2 remains, and the moving means 54 moves in the moving direction 31 along the dicing line 37a.

The blade 29 is constantly driven to rotate at a constant rotation speed by the rotation driving means 53. When the blade 29 advances in the moving direction 31 and reaches a position p2 which is a predetermined distance before the boundary position p3 with the semiconductor chip forming portion 34, the blade 29 is moved in the z direction by the height displacing means 55 to cut the cutting groove. The bottom 47 is displaced so as to gradually become deeper. At this time, before the position p2,
The moving speed 54 of the moving direction 54 of the blade 29 in the moving direction 31 is set to be less than the speed v1 at the boundary position p3. Thus, the semiconductor chip forming unit 34 determines whether the position cut by the blade 29 at the positions p3 to p4 has reached the semiconductor chip forming unit 34, and if so, in the next step s5, the position p3 The dicing operation is performed by the full dicing method in step s5. In step s5, the blade 29 cuts over the entire thickness of the semiconductor wafer 23, and the bottom 48 reaches halfway in the thickness direction of the wafer sheet 22.

Until the blade 29 reaches the boundary position p4 on the downstream side in the moving direction 31 of the semiconductor chip forming section 34 along the dicing line 37a, the flow rate q1 of the cutting water supplied from the nozzle 43 via the flow rate control valve 57 , Q2 are
It is kept at a constant value.

In step s6 of FIG. 5, it is determined whether the peripheral portion 33 has been reached again from the position p4 along the dicing line 37a. If so, in step s7, a dicing operation is performed by the semi-full dicing method.
At this time, in the peripheral portion 33, the moving speed of the blade 29 by the moving means 54 is increased to a predetermined position p5,
The speed v3 is maintained from the position p5 to the position p6 at the most downstream end along the moving direction 31 of the peripheral portion 33 and thereafter. The moving speed of the blade 29 along the moving direction 31 is v2 <v
1 <v3. The flow rate of the water from the nozzle 43 is from the flow rate q2 to the position p4 from the position p4 to the position p41.
And then maintained at a constant flow rate q3 (q1
= Q2> q3).

The moving speed of the blade 29 in the moving direction 31 is set to be higher in the peripheral portion 33 than in the semiconductor chip forming portion 34 (v1 <v2), whereby a load such as clogging of the blade 29 in the peripheral portion 33 is reduced. In the state of small influence, work efficiency is increased so that dicing is completed in the shortest possible time. In the peripheral portion 33 on the downstream side in the moving direction 31, the speed is higher than that of the semiconductor chip forming portion 34 (v
2 <v1 <v3), thereby suppressing separation of the semiconductor chip 35 and the end piece 36 from the wafer sheet 22 by the cutting water from the nozzle 43. When cutting the peripheral portion 33 downstream of the moving direction 31 after cutting the semiconductor chip forming portion 34, the flow rate q3 of the cutting water shown in FIG. 2 (3) is reduced (q2> q3), and the peripheral portion 33 is cut. The peeling of the semiconductor chip 35 and the end piece 36 in the vicinity is prevented.
Thus, according to the present invention, the dicing operation can be automatically performed without separating the semiconductor chip 35 and the end piece 36 from the wafer sheet 22.

In the peripheral portion 33, the bottom of the cutting groove cut by the blade 29 becomes shallower in the moving direction as indicated by reference numeral 49 in FIG. At the bottom 50, the semiconductor wafer 2
The thickness d2 is maintained from the back surface 24 of the third substrate 3.

In step s8, it is determined whether or not there is another line adjacent to the first dicing line 37 in the y direction for performing the dicing operation. When the next first dicing line is present, the above-described step s2 is performed. ~
s7 is repeated. All first dicing lines 37
When the dicing operation is completed, in step s9,
The table 26 is angularly displaced about the axis 27, and in step s10, a dicing operation is sequentially performed using the blade 29 along the second dicing line 38.
The dicing operation in step s10 is the same as the dicing operation in steps s2 to s7 described above. Thus, in step s11, all the second dicing lines 3
When the dicing operation of No. 8 is completed, all the dicing operations are ended in step s12.

[0047]

According to the present invention, the semiconductor chips can be separated from the wafer sheet without increasing the adhesive strength of the wafer sheet to the back surface of the semiconductor wafer and without damaging the semiconductor chips after dicing. At this time, the peripheral portion is partially cut in the thickness direction from the surface of the semiconductor wafer, and a portion not cut in the thickness direction remains on the wafer sheet side. Therefore, at the time of dicing, it is possible to reliably prevent the semiconductor chips and end pieces near the peripheral portion from peeling off from the wafer sheet.

Further, in the semiconductor chip forming portion which is more inward than the peripheral portion surrounded by the peripheral portion, the semiconductor chip is cut to the entire thickness and cut, so that it is not necessary to divide the semiconductor chip. No cracking occurs. In this way, the possibility that the semiconductor chips and the end pieces are separated from the wafer sheet in the vicinity of the peripheral portion and scattered is eliminated, thereby preventing damage to the blade, extending the life of the blade, and improving the productivity, workability and yield of the semiconductor chip. Can be improved.

According to the present invention, the thickness d2 left uncut in the peripheral portion is selected to be 10 to 100 μm, thereby preventing peeling of the semiconductor chips and end pieces from the wafer sheet in the peripheral portion, and It is ensured that chipping and cracking of the semiconductor chip and the end piece near the peripheral portion are prevented.

According to the present invention, the moving speeds v1 and v3 of the blade in the peripheral portion are set higher than the speed v2 in the semiconductor chip forming portion, and the moving speed v3 in the peripheral portion on the downstream side in the moving direction is further increased ( v1 <v3), and thus the separation of the semiconductor chip and the end piece from the wafer sheet near the peripheral portion on the downstream side in the moving direction can be reliably prevented, the dicing time can be reduced, and the productivity can be improved.

According to the present invention, the flow rate of the cutting water is reduced (q1 <
q3, q2 <q3), whereby the peeling of the semiconductor chip and the end piece in the vicinity of the downstream peripheral portion can be prevented more reliably.

According to the semiconductor wafer structure of the present invention, the semiconductor chip and the end piece near the peripheral portion do not peel off from the wafer sheet, and the semiconductor wafer is folded at a portion where the peripheral portion has been cut in the thickness direction. To reduce the size of the end pieces, simplifying the subsequent work process, for example, expanding the stretchable wafer sheet to make the spacing of the semiconductor chips on the wafer sheet uniform, for example, die bonding, etc. Workability can be improved.

According to the semiconductor wafer dicing apparatus of the present invention, the semiconductor wafer is diced without causing the semiconductor chips to peel off from the wafer sheet during the dicing, and without removing the peripheral end pieces from the wafer sheet. Can be automatically performed.

[Brief description of the drawings]

FIG. 1 is a simplified cross-sectional view showing a configuration of an embodiment of the present invention.

FIG. 2 is a view for explaining an operation of dicing a semiconductor wafer by a blade.

FIG. 3 is a vertical cross-sectional view taken along the line III-III in FIG. 2 (1).

FIG. 4 is a block diagram showing an electrical configuration of the semiconductor wafer dicing apparatus 21 according to the embodiment of the present invention shown in FIGS. 1 to 3;

FIG. 5 is a flowchart for explaining the operation of the processing circuit 52 shown in FIG. 4;

FIG. 6 is a cross-sectional view showing a dicing step of the first prior art.

7 is a plan view of the semiconductor wafer 2 according to the first prior art shown in FIG.

FIG. 8 is a simplified cross-sectional view of another second prior art which solves the problem of the full dice system shown in FIGS. 6 and 7.

FIG. 9 is a simplified plan view for explaining a third prior art.

[Explanation of symbols]

 Reference Signs List 21 Dicing device for semiconductor wafer 22 Wafer sheet 23 Semiconductor wafer 24 Back surface 25 Semiconductor wafer structure 29 Blade 31 Moving direction 33 Peripheral portion 34 Semiconductor chip forming portion 35 Semiconductor chip 36 End piece 37, 37a First dicing line 38 Second dicing line 41 outer peripheral part 42 surface 43 nozzle 52 processing circuit 53 rotation driving means 54 moving means 55 height displacement means 56 angular displacement means 57 flow control valve

Claims (6)

[Claims] In a state where the back surface of a semiconductor wafer is adhered to a wafer sheet, a peripheral portion of the semiconductor wafer is partially diced in a thickness direction from a surface of the semiconductor wafer, and a semiconductor chip surrounded by the peripheral portion is provided. A dicing method of a semiconductor wafer, wherein a dicing is performed by cutting a forming portion over the entire thickness direction. 2. The remaining thickness of the peripheral portion is 10 to 1
2. The dicing method for a semiconductor wafer according to claim 1, wherein the dicing is performed so as to be 00 μm. 3. The rotating speed of the dicing blade is maintained at a predetermined constant value, and the moving speed of the dicing blade along the dicing line is set higher at the peripheral portion on the upstream side in the moving direction than the semiconductor chip forming portion. 3. The dicing method for a semiconductor wafer according to claim 1, wherein the peripheral speed on the downstream side in the direction is higher than the peripheral speed on the upstream side in the moving direction. 4. A cutting water is jetted toward a cutting portion of a semiconductor wafer by a dicing blade, and a flow rate of the cutting water is reduced during cutting of a peripheral portion after cutting of a semiconductor chip forming portion. Claims 1-3
The dicing method of a semiconductor wafer according to any one of the above. 5. A back surface of a semiconductor wafer is adhered to a wafer sheet, and a cut portion is formed along a plurality of dicing lines. In each dicing line, a peripheral portion of the semiconductor wafer is partially cut in a thickness direction from a front surface in a thickness direction. A semiconductor wafer structure, wherein the remaining thickness is 10 to 100 μm, and the semiconductor chip forming portion surrounded by the peripheral portion is cut and cut in the entire thickness direction. 6. A dicing table on which a wafer sheet to which a back surface of a semiconductor wafer is adhered is mounted, a dicing blade arranged above the table and driven to rotate, and a table and a dicing blade are mounted on the table. A moving means for moving in parallel to the surface and displacing vertically toward and away from the mounting surface; and partially dicing the peripheral portion of the semiconductor wafer on the table from the surface of the semiconductor wafer in the thickness direction. A dicing apparatus for semiconductor wafers, comprising: a control unit that controls a moving displacement unit so that the enclosed semiconductor chip forming unit cuts and dices all over the thickness direction.