JPH1110549A - Cutting blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the sectional form from being U-shaped even if the knife edge wears away so as to keep the uniform cut line of a semiconductor wafer by giving an angle to the cutting part to be formed in such a manner as to have a V-shaped section, and making the central part and the other parts different in wear rate of friction material. SOLUTION: A cutting blade 9 has such a three-layer structure that an angle is given to the outer peripheral surface of a cutting part 9a to be formed substantially V-shaped, and in its sectional form, the central part 13 and the side parts 14, 14 are formed, and further it has such a structure that the central part 13 has a higher hardness of deposited nickel plating as compared with the side parts 14, 14. That is, the properly that when an organic additive is added to a plating solution, the hardness of nickel plating is hightened is utilized so that two kinds of plating solutions, the plating solution to which the additive is added and the plating solution to which the additive is not added can be used properly to form the nickel plating. As the central part has such a high hardness that it is hard to wear away, the knife edge 9a can keep the substantially V-shaped condition over a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting blade for dicing a semiconductor wafer, and more particularly to a technique for controlling wear of a cutting edge to prevent chipping and cracking from occurring during dicing.

[0002]

2. Description of the Related Art In semiconductor manufacturing, a semiconductor wafer having undergone a pattern forming step is cut into dice by a dicing step and divided into chips.

[0003] This apparatus for cutting a semiconductor wafer is called a dicer, in which a thin-blade cutting blade (peripheral blade) is attached to a high-speed rotating spindle, and the semiconductor wafer fixed to a tape is cut by the cutting blade. It is.

[0004] Since a semiconductor wafer is coated with various materials or is combined with various materials in a process until a semiconductor chip is finally formed, cutting of the semiconductor wafer is performed in a dicing process. Is not a single material but a composite material, so that various problems occur when cutting a single material.

For example, if an oxide film or aluminum wiring formed on the surface of a semiconductor wafer in a pattern forming step remains on a cutting line of the semiconductor wafer, cutting defects such as clogging and blinding of a cutting blade occur. Accordingly, problems such as chipping on the back surface of the semiconductor wafer and side cracks of the chip occur.

As a countermeasure against the above problem, FIG.
As shown in the figure, a cutting blade a (hereinafter, referred to as a “V-shaped blade”) having a substantially V-shaped cross section at an angle to a cutting portion (edge)
That. ), A V-shaped cut line is formed on the surface of the semiconductor wafer b to remove the oxide film, the aluminum wiring, and the like, and then completely cut (full cut) with the cut line using a normally shaped cutting blade c. A cutting method (bevel cutting) is used.

[0007]

In the V-shaped blade a, as shown in FIG. 11, during use, the edge, which was initially substantially V-shaped, wears out and becomes substantially U-shaped in cross section.
It becomes letter-shaped. Therefore, while the edge is substantially V-shaped, the width of the cut line can be kept constant by adjusting the height, but when the edge becomes substantially U-shaped, the height is reduced. Even if the width of the cut line is adjusted to a certain value by adjusting the width of the cut line, the width of the cut line greatly varies due to the variation in the thickness of the semiconductor wafer b. In some cases, the active area where the chip is formed is diced. The oxide film or aluminum wiring etc. on the surface of the semiconductor wafer cannot be sufficiently removed because the amount of the cutting edge biting into the surface of the semiconductor wafer becomes shallow. Subsequent chipping may occur in the semiconductor wafer during full cutting with a normal cutting blade.

Therefore, the cutting blade of the present invention prevents the cross-sectional shape from becoming substantially U-shaped even when the cutting edge is worn, and keeps the cut line of the semiconductor wafer uniform.
It is an object to prevent occurrence of chipping at the time of a subsequent full cut.

[0009]

According to the present invention, there is provided a cutting blade comprising:
In order to solve the above-mentioned problem, the cut portion is formed to have a substantially V-shaped cross-sectional shape at an angle, and has a different wear rate between a central portion in a thickness direction and other portions in the thickness direction. .

Therefore, by adjusting the wear rates of the central portion and the other portions as appropriate, it becomes possible to maintain the substantially V-shaped shape of the cut portion.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the cutting blade of the present invention will be described below in detail with reference to the accompanying drawings.

In a dicing step in a semiconductor product manufacturing process, a dicing apparatus (dicer) 1 chucks a semiconductor wafer 4 fixed to a frame 3 via an adhesive tape 2 as shown in FIGS. This device is fixed on the king table 5, moves the chuck table 5, adjusts the alignment, and then dices by the cutting means 6 to divide the chip into chips.

As shown in FIG. 2, the cutting means 6 comprises spindles 7, 7 arranged in parallel and rotating at high speed, and cutting blades 8, 9 having a substantially ring shape fixed to the spindles 7, 7 by an appropriate method. It is made up of

The cutting blades 8 and 9 are formed by fixing diamond abrasive grains with nickel or the like by, for example, electrolytic plating or electroless plating.
The outer peripheral side is the cutting portions 8a and 9a. Here, the cutting blade 8 is not related to the present invention, but the cutting blade 9 is related to the present invention. Therefore, only the cutting blade 9 will be described in detail.

The cutting blade 8 and the cutting blade 9
As shown in FIG. 3, a plating solution tank 11 provided with a stage 10 for depositing nickel therein is used. The plating solution tank 11 is filled with a nickel plating solution mixed with diamond particles serving as abrasive grains. It is manufactured by utilizing the fact that a nickel-plated layer containing diamond particles is formed on the stage 10 by filling it with 12 and stirring it. Although the above is the case of electroless plating, in the case of electrolytic plating, the stage 10 serves as an anode.

The cutting blade 8 is formed of a uniform material by the above manufacturing method. The cutting blade 9 has a cutting portion 9 as shown in FIG.
The outer peripheral surface of a is formed in a substantially V-shape with an angle, and has a three-layer structure including a central portion 13 and side portions 14 and 14 in a cross-sectional shape. 14 and 14, it has a structure in which the hardness of the deposited nickel plating is higher.

FIGS. 5 and 6 show first and second modified examples 9A and 9B of the cutting blade, respectively. That is, the cutting blade 9A is
Unlike the above, a three-layer structure is not clearly formed, but the hardness of the deposited nickel plating becomes lower from the central portion 15 to the side portions 16. In addition, the cutting blade 9B has a density of diamond, which is an abrasive, from the central portion 17 to both side portions 18,
It has a structure that gradually decreases as it goes to 18.

These cutting blades 9, 9A and 9B are:
It can be formed by the following method obtained by improving the manufacturing method using the plating solution layer 11 described above.

That is, as described above, the plating solution tank 11 in which the stage 10 for depositing nickel is provided is used, and the plating solution tank 11 is moved to the plating solution containing diamond particles serving as abrasive grains. By utilizing the fact that a nickel-plated layer containing diamond particles is formed on the stage 10 by filling and agitating the same with the center 12 and the center portion 13 and the side portions, like the cutting blades 9 and 9A. The following method is used when the nickel plating is formed so as to have partially different hardnesses, such as 14, 14, the central portion 15, and the side portions 16, 16.

That is, by using the property that the hardness of nickel plating increases when an organic additive is added to the plating solution 12, two types of plating solutions, one with the above additive and one without the additive, are used separately. Can be formed by

For example, first, the cutting blades 9 and 9A use an ordinary plating solution 12 to deposit a portion corresponding to one of the side surfaces 14 or 16, and then add an additive to the plating solution 12. Then, a portion corresponding to the central portion 13 or 15 is precipitated, and the remaining side portion 14 or 16 is again formed using the ordinary plating solution 12 to which no additive is added.
Is formed by precipitating a portion corresponding to.

In the case of a cutting blade 9B in which the density containing abrasive grains such as diamond is changed between the side portions 18, 18 and the central portion 17, the first half of the plating process is gradually performed from the start of plating. When the amount of diamond particles in the plating solution 12 is increased in the plating solution 12 and the addition of diamond particles to the plating solution 12 is stopped at an intermediate point in the process, the second half of the diamond in the plating solution 12 together with nickel is performed. Since the amount of diamond particles in the plating solution 12 inevitably decreases due to the continued precipitation of the particles, the amount of diamond particles precipitated together with nickel decreases, and the central part 1 where the density of diamond abrasive grains is high is reduced.
7 and side portions 18, 18 having a low density of diamond abrasive grains
Can be formed. In the above-mentioned deposition step, it is also possible to use a method of gradually removing the abrasive grains of diamond in the plating solution 12 using a filter after the central portion 17 is formed.

Further, instead of filling the plating solution 12 in the plating solution tank 11, the plating solution is jetted from a nozzle (not shown) to the stage 10 so that nickel plating is deposited on the stage 10 so that the cutting blade 9, It is also possible to form 9A and 9B. Then, in this method, by adjusting the concentration of the additive and the amount of diamond particles in the plating solution 12 ejected from the nozzle, the cutting blades 9, 9A and 9B are appropriately formed similarly to the above method.
Can be formed.

The cutting edges of the cutting blades 9, 9A and 9B formed as described above are thereafter formed in a substantially V-shape by an appropriate method.

Thus, the cutting blades 9, 9A and 9B
When used for dicing the semiconductor wafer 4, in the cutting blade 9, the central portion 13 where the nickel plating is hard is slowly worn, and conversely, the side portions 14 and 14 where the nickel plating is relatively soft. Since the wear is rapid, the shape of the cutting portion 9a changes from the state shown on the left side of FIG. 7 to the state shown on the right side due to the wear.

In the cutting blade 9A, the wear of the central portion 15 where the nickel plating is hard is slow,
Conversely, the side portion 1 where the nickel plating is soft
Since the wear of 6 and 16 is early, the shape of the cutting portion 9a changes from the state shown on the left side of FIG. 8 to the state shown on the right side due to the wear.

Further, in the cutting blade 9B, the central portion 17 where the density of diamond particles is high during nickel plating is slow in wear, and conversely, the density of diamond particles during nickel plating is low. Since the side parts 18, 18 wear faster, the shape thereof changes from the state shown on the left side of FIG. 9 to the state shown on the right side due to the wear.

Thus, the cutting blades 9, 9A and 9
B has a high hardness at the central portions 13, 15, and 17 and is hard to wear, so that the cutting edge 9a can maintain a sharp V-shaped state for a long period of time, and can be worn in a substantially U-shape. Absent.

In order to change the abrasion rate between the central portion and the side portions, at least three or more materials having different properties are stacked, and the cutting blade of the present invention may be manufactured by joining with an adhesive or joining by heating. It is possible.

The shape of the cutting blade is not only fixed to the spindle by being sandwiched between metal disks as shown in the above-described embodiment and each modified example, but also integrally joined to a metal hub made of aluminum or the like. Some are fixed to a spindle by the metal hub.

[0031]

As is apparent from the above description, the cutting blade of the present invention has a cutting portion formed at an angle in a substantially V-shaped cross-sectional shape, and a central portion and a side portion in the thickness direction. Since the constituent materials have different wear rates, the V-shaped shape of the cut portion can be maintained by appropriately adjusting the wear rates of the central portion and the other portions. In addition, it is possible to prevent chipping from occurring when cutting the semiconductor wafer.

According to the second aspect of the present invention, there is provided a center portion having a high hardness to be hardly worn, and a center portion sandwiching the center portion and having a lower hardness than the center portion and having a relatively low hardness. Since the cut portion is formed in a three-layer structure with the side portions made easy to be worn, the cut portion can maintain a substantially V-shaped shape due to the central portion that is hard to wear.

According to the third aspect of the present invention, since the hardness is gradually increased from the side portion to the center portion so as to prevent wear, the shape of the cut portion is substantially V
It can be kept in a letter shape.

Further, in the inventions according to the fourth and fifth aspects, since the density of abrasive grains such as diamond is gradually increased from the side portions to the center portion, the abrasive grains are formed so as to be hardly worn. In addition, the cut portion can maintain a substantially V-shaped shape due to the central portion that is not easily worn.

[0035] In the invention described in claim 6, the central portion where the abrasive grain density is increased to make it hard to wear, and the central portion is sandwiched between the central portion and the abrasive grain density is relatively lower than the central portion. Since it is formed in a three-layer structure with the side portions that are easily worn, the cut portion can maintain a substantially V-shaped shape due to the central portion that is hardly worn.

Furthermore, in the invention according to claim 7, the central part in which the grain size of the abrasive grains is increased to make the abrasive grain hard to wear, and the central part is located so as to sandwich the central part and is more abrasive than the central part. The cutting portion can be maintained in a substantially V-shape by the central portion that is hard to wear because it is formed in a three-layer structure with the side portion that is relatively easy to wear and the grain size is small.

According to the present invention, since a plurality of materials having different properties are bonded to each other, the cutting portion is maintained in a substantially V-shaped shape. The properties of each part of the blade can be freely set.

It should be noted that the specific shapes and structures of the respective parts shown in the above-described embodiment are merely examples for embodying the present invention, and the technical features of the present invention are not limited thereto. It should not be construed that the scope is limited.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a cutting blade of the present invention together with FIGS. 2 to 9, and is a perspective view schematically showing a dicing apparatus.

FIG. 2 is a perspective view showing a cutting unit.

FIG. 3 is a view schematically showing a method for manufacturing a cutting blade.

FIG. 4 is a sectional view of a cutting blade.

FIG. 5 is a sectional view showing a first modification of the cutting blade.

FIG. 6 is a sectional view showing a second modification of the cutting blade.

FIG. 7 is a cross-sectional view showing a change in a cutting portion due to wear of the cutting blade.

FIG. 8 is a cross-sectional view showing a change in a cutting portion due to wear of a cutting blade in a first modification.

FIG. 9 is a cross-sectional view illustrating a change in a cutting portion due to wear of a cutting blade in a second modified example.

FIG. 10 is a diagram schematically showing dicing of a semiconductor wafer by a bevel cut method.

FIG. 11 is a diagram showing a change due to wear of a conventional cutting blade.

[Explanation of symbols]

9 cutting blade, 9a cutting part, 13 central part, 14
... Side part, 9A ... Cutting blade, 15 ... Central part, 16 ...
Side surface, 9B: Cutting blade, 17: Central part, 18: Side surface

Claims (10)

[Claims] 1. A cutting blade formed by fixing abrasive grains of diamond or the like with nickel or the like by electrolytic plating or electroless plating, wherein a cutting portion is formed in a substantially V-shaped cross section at an angle, A cutting blade having different wear rates at a central portion and other portions in a thickness direction. 2. A three-layer structure comprising a central portion having a high hardness to prevent abrasion and a side portion located so as to sandwich the central portion and having a lower hardness than the central portion and relatively easy to wear. The cutting blade according to claim 1, wherein: 3. The cutting blade according to claim 1, wherein the cutting blade is formed so that the hardness is gradually increased from a side surface portion to a central portion in a thickness direction so as to be hard to wear. 4. The cutting blade according to claim 1, wherein the density of abrasive grains such as diamond is gradually increased from a side surface portion to a center portion in a thickness direction so as to be hard to wear. 5. The cutting blade according to claim 3, wherein the density of abrasive grains such as diamond is gradually increased from a side surface portion to a center portion in a thickness direction so as to be hard to wear. 6. A central portion having a high abrasive grain density to prevent wear, and a side portion located so as to sandwich the central portion and having a lower abrasive grain density than the central portion and relatively easy to wear. The cutting blade according to claim 1, wherein the cutting blade is formed in a layered structure. 7. A central portion in which the grain size of the abrasive grains is increased so as to be less likely to be worn, and a side face which is located so as to sandwich the central portion and has a smaller grain size than the central portion and is relatively easily worn. 2. A three-layer structure comprising:
A cutting blade according to claim 1. 8. The method according to claim 2, wherein the material is formed by laminating a plurality of materials having different properties.
Cutting blade described in 9. The method according to claim 6, wherein the material is formed by laminating a plurality of materials having different properties.
Cutting blade described in 10. The cutting blade according to claim 7, wherein the cutting blade is formed by laminating a plurality of materials having different properties.