JP3968924B2 - Single layer whetstone and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a single-layer grindstone used for conditioning a polishing pad used when a surface of a material to be polished such as a semiconductor wafer is polished by a CMP apparatus, and a manufacturing method thereof .
[0002]
[Prior art]
Conventionally, there is an apparatus as shown in FIG. 7 as an example of a CMP apparatus (chemical mechanical polishing machine) that chemically and mechanically polishes the surface of a semiconductor wafer (hereinafter simply referred to as a wafer) cut out from a silicon ingot.
Wafers are required to be mirror-polished so as to have a highly accurate and defect-free surface as devices become finer. The polishing mechanism by CMP is based on a mechano-chemical polishing method in which a mechanical element (free abrasive grains) made of fine particle silica or the like and an etching element made of an alkali liquid or an acidic liquid are combined.
In the CMP apparatus 1, a polishing pad 4 made of, for example, hard urethane is provided on a disc-shaped rotary table 3 attached to a central shaft 2 as shown in FIG. A wafer carrier 5 capable of rotating at a position eccentric from the central axis 2 of the pad 4 is disposed. The wafer carrier 5 has a disk shape smaller in diameter than the pad 4 and holds the wafer 6. The wafer 6 is disposed between the wafer carrier 5 and the pad 4 and is used for polishing the surface on the pad 4 side. And mirror finished.
[0003]
At the time of polishing, for example, the above-mentioned free abrasive grains made of fine particle silica or the like are used as an abrasive, and a mixture of an alkali solution for etching and the like is supplied onto the pad 4 as a liquid slurry s. Since the slurry s flows between the wafer 6 held by the wafer carrier 5 and the pad 4, the wafer 6 rotates by the wafer carrier 5, and at the same time, the pad 4 rotates around the central axis 2 in the P direction, for example. Further, one surface of the wafer 6 is polished by the pad 4.
A number of fine foam layers for holding the slurry s are provided on the pad 4 made of hard urethane or the like for polishing the wafer 6, and the wafer 6 is polished by the slurry s held in these foam layers. Is called.
However, since the polishing of the wafer 6 is repeated, the flatness of the polishing surface of the pad 4 is reduced or clogged, resulting in a problem that the polishing accuracy and polishing efficiency of the wafer 6 are reduced.
[0004]
Therefore, the CMP apparatus 1 has conventionally been provided with a pad conditioner 8 as shown in FIG. 7, and the surface of the pad 4 is reground (conditioning).
In this pad conditioner 8, a wheel 11 is provided on a turning shaft / rotary shaft 9 provided outside the rotary table 3 via an arm 10, and the wheel 11 is rotated in the same direction as the pad 4 by the rotary shaft 9. Thus, the surface of the pad 4 is polished on the rotating pad 4 to recover or maintain the flatness of the surface of the pad 4 and to eliminate clogging. Further, the wheel 11 may be swung in addition to the rotational movement.
As shown in FIGS. 8 (A) and 8 (B), the wheel 11 has a circular plate-like base metal 12 with a flat top surface and a ring-shaped abrasive layer 13 having a constant width. For example, as shown in FIG. 9, the abrasive grain layer 13 is formed by dispersing and fixing superabrasive grains 14 such as diamond and cBN on a base metal 12 by a metal binder phase 15 by electroplating or active brazing. . The metal binder phase 15 is made of, for example, nickel plating.
In addition, the groove 17 is formed in the radial direction on the surface of the abrasive grain layer 13 at a predetermined interval such as 45 °, and the slurry s and the cutting waste are discharged to the outside through the groove 17.
[0005]
[Problems to be solved by the invention]
By the way, when the pad 4 is ground using such a wheel 11, the wheel 11 is required to have a stable grinding performance and particularly needs to be stable over time. The wheel 11 as a conditioner is as follows. Has a problem.
Grinding debris made of silicon wafer wiring metal or silicon remaining on the pad 4 during conditioning adheres between the superabrasive grains 14 of the wheel 11 and eventually solidifies together with the slurry s to become debris. The superabrasive grains 14 are buried in the adhering scrap, and the grinding ability with respect to the pad 4 is lowered.
Further, the superabrasive grains 14 are worn away by the grinding of the pad 4 and contact with various grinding scraps, and the sharpness is lowered.
[0006]
In view of such circumstances, the present invention is a single-layer grindstone that can effectively discharge by suppressing the accumulation and retention of various grinding scraps and solidified slurries between superabrasive grains, and the production thereof. It aims to provide a method .
[0007]
[Means for Solving the Problems]
The single-layer grindstone according to the present invention is a single-layer grindstone in which a superabrasive grain fixed to a metal binder phase is mounted on a base metal. A plurality of small abrasive layer portions are formed and arranged, and the small abrasive layer portion is formed in a cylindrical shape in which the opening having a circular cross section is formed at the center and is raised on the base metal at a predetermined interval. The superabrasive grains are formed in a ring shape on the upper surface of the mound-shaped mound portion . By providing an opening for supplying the grinding fluid to the surrounding superabrasives at the approximate center of the small abrasive layer, the grinding fluid can be supplied directly to the grinding point by the superabrasives, and various grinding debris can be superabrasive. It can be discharged without causing any accumulation of deposits, and the viscosity of the grinding fluid can be reduced by mixing the grinding scraps, and the discharge can be performed smoothly. Cooling of the superabrasive grains can be promoted and damage can be suppressed. The single-layer grindstone refers to a grindstone in which only one superabrasive grain is fixed in the thickness direction of the metal binder phase, and includes both electrodeposition grindstones and metal bond grindstones.
[0008]
Further, the small abrasive layer portion is formed on the mound portion that rises at a predetermined interval on the base metal , and thus the work material is formed by forming the small abrasive layer portion on the mound that protrudes on the base metal. Even if it is a soft pad such as a pad of a CMP device, it is grounded by contact with only the superabrasive grains in the small abrasive layer part without grinding, so the grinding pressure is high, the sharpness is good, and the grinding dust is discharged Also good. A discharge path may be formed in a region other than the mound portion. The supply source and discharge path of the grinding fluid are arranged on both sides of the grinding point of the small abrasive layer part, so that the distance between both can be shortened as much as possible, and the grinding fluid is sufficiently distributed to the grinding point. It is possible to wash away smoothly by preventing grinding debris from accumulating.
[0009]
Further, the opening of the small abrasive layer portion may have a diameter of φ0.5 to 3.0 mm.
If the diameter (d) of the opening is smaller than 0.5 mm, the grinding liquid cannot be sufficiently supplied to the grinding point, and if it exceeds 3.0 mm, the small abrasive layer portion existing ratio decreases and the grinding ability decreases, which is not preferable.
The diameter (D) of the mound portion may be 2 to 10 times the diameter (d) of the opening.
If it is in the range of 2 to 10 times the diameter (d) of the opening, it is possible to prevent the accumulation of grinding debris at the grinding point and to wash away smoothly.
The height of the mound part relative to the base metal may be in the range of 0.1 to 5.0 mm.
If it is this range, a grinding fluid and a grinding | polishing waste can be easily poured and discharged between a grinding point and the discharge path on a base metal.
[0010]
The distance (L) between adjacent mound parts may be in the range of 1/3 to 2 times the average diameter (D) of the mound parts.
If it is this range, the space | interval of a small abrasive grain layer part can be set appropriately, the grinding pressure of a superabrasive grain can be maintained high, and various grinding | debris can be smoothly discharged | emitted with a grinding fluid through this clearance gap.
The abrasive layer may be formed in a plurality of ring-shaped or spiral shapes.
As a result, the sum of the grinding lengths of the respective abrasive grain layers in the direction substantially parallel to the relative movement direction of the work material can be made substantially uniform at an arbitrary position in the direction substantially perpendicular to the movement direction of the work material. Further, if the abrasive layer is composed of three or more layers, the sum of the areas of the abrasive layer regions at arbitrary positions substantially orthogonal to the direction substantially parallel to the relative movement direction of the work material can be easily made uniform. .
A discharge path may be formed between a plurality of abrasive grain layers arranged at intervals in the radial direction.
In this case, the discharge path forms a ring-shaped or spiral shape with a sub-discharge path formed between adjacent small abrasive layer portions in each abrasive layer, and a plurality of abrasive layers adjacent in the radial direction. It may consist of a main discharge channel in between. Various grinding debris generated by grinding in the small abrasive layer portion is washed out together with the grinding liquid supplied from the opening of the small abrasive layer portion, flows through the sub discharge path, and further discharged to the outside through the main discharge path, Grinding debris can be easily discharged and accumulation of accumulated particles between superabrasive grains can be suppressed.
This single-layer grindstone is particularly suitable as a pad conditioner for a CMP apparatus.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 4 relate to the first embodiment, FIG. 1 is a plan view of a surface on which a wheel abrasive layer is mounted, and FIG. 2 is a middle layer of the wheel abrasive layer shown in FIG. FIG. 3 is a longitudinal sectional view taken along the line BB of the abrasive grain layer shown in FIG. 2, and FIGS. 4A, 4B, and 4C are views showing a manufacturing process of the wheel according to the embodiment. is there.
The wheel 20 (single layer grindstone) according to the embodiment shown in FIG. 1 is concentric (not concentric) on the outer peripheral side of one surface 22a forming a substantially circular shape of a disk-shaped base metal 22 as shown in FIGS. Abrasive grain layer 24 composed of a plurality of layers (three layers in the figure) forming a ring shape may be provided. The abrasive grain layer 24 is formed with a first abrasive grain layer 24A having a maximum diameter (for example, the same diameter as the base metal 22) on the outermost peripheral side, and a second abrasive grain layer 24B is formed on the inner side with a gap therebetween. A third abrasive grain layer 24C having a minimum diameter is formed on the inside. No abrasive layer is formed inside the third abrasive layer 24C.
[0012]
In the one surface 22a of the base metal 22, the ring-shaped regions of the first to third abrasive layers 24A, B, and C are set to have a height that is higher in the thickness direction than the other regions (for example, the height shown in FIG. This is referred to as a first base metal part 22A, a second base metal part 22B, and a third base metal part 22C.
2 and 3, a plurality of substantially cylindrical mound portions 25 are formed at predetermined intervals, and an opening 26 having a circular cross section is formed at the center thereof. Then, a substantially ring-shaped small abrasive layer portion 28 is formed on the upper surface of the mound portion 25. The small abrasive layer portion 28 is formed of a metal bonding phase (metal plating phase) 15 of Ni or Ni alloy such as diamond or CBN. Superabrasive grains 14 are dispersed and fixed. In the small abrasive layer portion 28, only one superabrasive grain 14 is arranged in the thickness direction, and is manufactured by, for example, electroplating. In FIG. 2, some superabrasive grains 14 are omitted.
A large number of small abrasive layer portions 28 having the same configuration are also provided on the first base metal portion 22A and the third base metal portion 22C.
[0013]
As shown in FIG. 3, a water passage 30 is formed in the base metal 22 over the regions of the first to third abrasive layer portions 24A, 24B, 24C. This water passage 30 communicates with an opening 26 formed at the center of each small abrasive layer portion 28 of the first to third abrasive layers 24A, 24B, and 24C. Water is supplied, circulates in the water passage 30, and is discharged from each opening 26 to the outside.
Here, the inner diameter d of the opening 26 is set to a range of 0.5 to 3 mm, for example, and the diameter D of the mound portion 25 is set to a range of 2d to 10d. Further, the height h of each of the mound portions 25 from the base metal portions 22A, 22B, and 22C is set in a range of 0.1 to 5 mm. Further, the distance L between two adjacent mound portions 25, 25 is in the range of 1/3 to 2 times the diameter D of the mound portion 25.
[0014]
And between each adjacent mound part 25,25 in each base metal part 22A, B, C, for example, the sub discharge path 32 which makes mesh shape is constituted, and the abrasive grain layer is not formed in this sub discharge path 32 Then, the grinding scraps of the pad 4 and the solidified product of the slurry s are discharged by the grinding liquid. Further, a substantially ring-shaped main discharge passage 34 is formed in the gap between the first to third abrasive layer 24A, B, C. The main discharge passages 34, 34 are wider than the sub discharge passage 32 and are formed deeper than the step H of the base metal portions 22A, 22B, 22C by the same distance.
Further, the first to third abrasive grain layers 24A, B, and C are formed with concave grooves 17 for discharging the slurry s, grinding dust, and the like in the radial direction at predetermined intervals, for example, 45 ° intervals. In FIG. 1, the concave grooves 17 are formed in a line so as to form a straight line with respect to the first to third abrasive grain layers 24A, B, and C, and their bottom surfaces are set at substantially the same depth as the main discharge passage 34. ing.
The concave grooves 17 do not necessarily have to be formed in a line, and may be arranged in the radial direction by shifting to different positions in the circumferential direction in the first to third abrasive grain layers 24A, B, and C. . Moreover, you may increase the groove 17 of an outer layer with respect to an inner layer. If formed in this way, the cooling efficiency and the discharge performance of the grinding dust are good between the first to third abrasive grain layers 24A, B, and C.
[0015]
The wheel 20 according to the present embodiment is configured as described above. Next, a method for manufacturing the wheel 20 will be described with reference to FIG.
In FIG. 4A, for example, one surface 22a of the disk-shaped base metal 22 made of SUS304 or the like is partially removed by etching or the like to leave a plurality of layers of raised portions in a ring shape, and the first base metal part 22A, Assume that the second base metal part 22B and the third base metal part 22C. Of the portion removed by etching, the region between the base metal portions 22A, 22B, and 22C constitutes a main discharge path 34. In this way, one surface 22a of the base metal 22 is formed. The one surface 22a may be formed by molding or the like instead of etching.
A hollow water passage 30 is formed inside the base metal 22 in a region facing the first to third metal base portions 22A, 22B, and 22C. The water passage 30 is formed in the first to third base metal portions 22A. , B, and C communicate with openings 26 that are perforated at predetermined intervals.
[0016]
Next, in FIG. 4A, masking is performed leaving a region corresponding to the mound portion 25 around each opening 26 on the first to third base metal portions 22A, B, and C communicating with the water passage 30, and Ni or The plating is deposited in a substantially cylindrical shape so as to surround the periphery of the opening 26 by Ni-based alloy plating to form a large number of mound portions 25... Shown in FIG. Note that the mound portions 25 may be formed by etching or electric discharge machining instead of plating.
In addition, the area | region except the mound part 25 ... in each base metal part 22A, B, C comprises the sub discharge path 32. FIG.
4B, the main and auxiliary discharge passages 34 and 32 except for the mound portions 25 are masked with resin, and plating is performed while air is discharged from the water passages 30 through the respective openings 26. As a result, as shown in FIG. 4C, the superabrasive grains 14 are fixed to the upper surface of each mound portion 25 excluding the water passage 30 with a metallic binder phase 15 such as Ni. Note that plating may be performed on the mound portion 25 by discharging a plating solution containing the superabrasive grains 14 from each opening 26 through the water passage 30. In this case, plating is deposited on the water passage 30 but the superabrasive grains 14 are not fixed.
[0017]
By the way, in the first to third abrasive grain layers 24A, B, C having a predetermined interval in the radial direction, the widths Wa, Wb, Wc are the largest in the innermost abrasive grain layer 24C and are directed toward the outer layer. The width is set so that the width gradually decreases. Therefore, Wa <Wb <Wc. In addition, each width | variety of each 1st thru | or 3rd abrasive grain layer 24A, B, C becomes a fixed width, respectively.
In FIG. 1, the virtual lines a, b, c, and d at arbitrary positions in the direction substantially orthogonal to the rotation direction P of the pad 4 are inscribed in the respective abrasive grain layers 24A, B, and C in FIG. In this case, the grinding length (for example, the grinding length Ld1 of the imaginary line d) intersecting the outer abrasive layer having the larger diameter becomes larger than the grinding length intersecting the smaller abrasive layer having the inner diameter, and the amount of work during grinding is increased. This is because in order to increase the (grinding length), the width of the inner abrasive layer is increased to make the grinding length (work amount) of each abrasive layer more uniform.
[0018]
For example, an imaginary line extending in a direction substantially parallel to the rotation direction P of the pad 4 with respect to the first to third abrasive grain layers 24A, B, and C in FIG. The virtual lines a, b, c, d are drawn at the positions, for example, the virtual lines a, b intersect the first to third abrasive layer 24A, B, C, and the virtual line c circumscribes the third abrasive layer 24C. Then, the first and second abrasive grain layers 24A and 24B intersect, and the imaginary line d intersects with the first abrasive grain layer 24A. And the grinding length of the area | region of the 1st thru | or 3rd abrasive grain layer 24A, B, C where each virtual line a, b, c, d cross | intersects is set as follows.
The grinding lengths (areas) of the first to third abrasive grain layers 24A, 24B, 24C intersecting with an imaginary line a closest to the center O of the wheel 20 are La1, La2, La3, and the next closest imaginary center to the rotation center O. The grinding lengths (areas) of the first to third abrasive grain layers 24A, B, and C intersecting with the line b are Lb1, Lb2, and Lb3, and the first and second intersecting with an imaginary line c next to the rotation center O. The grinding length (area) of the two abrasive grain layers 24A and 24B is Lc1 and Lc2, and the grinding length (area) of the first abrasive grain layer 24A intersecting at the outer virtual line d farthest from the rotation center O is Ld1. Then
2 x (La1 + La2 + La3) ≒ 2 x (Lb1 + Lb2 + Lb3) ≒ 2 x (Lc1 + Lc2) ≒ 2 x (Ld1)
The widths Wa, Wb, Wc of the first to third abrasive layer 24A, B, C are set so that As a result, Wa <Wb <Wc.
[0019]
The wheel 20 according to the present embodiment has the above-described configuration, and when the pad 4 is conditioned, the wheel 20 is rotated while the pad 4 is rotated to grind the raising of the pad 4 to restore its flatness or Let it be maintained.
At the time of grinding, in each of the first to third abrasive grain layers 24A, B, and C of the abrasive grain layer 24, the pad 4 made of the superabrasive grain 14 from the opening 26 formed in the center thereof through the water passage 30. Grinding is performed while supplying a grinding fluid such as pure water to the grinding point.
As a result, the grinding scraps of the pad 4 generated by the grinding by the superabrasive grains 14 of the small abrasive layer portion 28, the wiring metal of the silicon wafer remaining on the pad 4, the silicon grinding scraps, etc. adhere between the superabrasive grains 14. Thus, the sticking is suppressed, the viscosity of the grinding fluid containing the grinding waste is lowered, and the discharge to the main discharge path 34 through the sub discharge path 32 is promoted. In addition, cooling of the superabrasive grains 14 can be promoted by the grinding liquid to prevent the superabrasive grains 14 from being damaged, and various grinding debris can be prevented from accumulating between the superabrasive grains 14 and 14.
[0020]
Therefore, the grinding waste of the pad 4 generated by the superabrasive grains 14 of the small abrasive grain layer portion 28 provided in each of the abrasive grain layers 24A, B, C, and other various grinding scraps are discharged from the openings 26. And is discharged through the auxiliary discharge path 32 around the small abrasive layer portion 28 without being clogged between the superabrasive grains 14 and further discharged to the outside through the main discharge path 34 and the guide groove 17. .
Moreover, the grinding point by the superabrasive grains 14 of each small abrasive grain layer portion 28 is such that the grinding liquid supplied from the adjacent opening 26 is sufficiently spread, and the grinding scraps are washed away without accumulating between the superabrasive grains 14. Further, the height h of the grinding point and the sub discharge path 32 is set to such an extent that the grinding fluid and grinding waste can be easily discharged.
[0021]
Furthermore, in the first to third abrasive grain layers 24A, B, and C of the abrasive grain layer 24, a plurality of virtual lines at arbitrary positions arranged by being shifted from the center O of the wheel 20 in a direction substantially perpendicular to the rotation direction P of the pad 4. Speaking of a, b, c, d, the sum of the grinding lengths on each virtual line (sum of areas) 2 × (La1 + La2 + La3), 2 × (Lb1 + Lb2 + Lb3), 2 × (Lc1 + Lc2), 2 × (Ld1) are mutually Since they are almost the same, as shown in FIG. 5, grinding can be performed with a substantially uniform work amount over the entire region in the swinging direction substantially orthogonal to the P direction of the abrasive grain layer 24.
Therefore, in the conditioning of the pad 4, the rocking motion is not necessarily required only by placing the wheel 20 on the pad 4 and rotating it, so that the pad 4 can be ground efficiently and with higher flatness.
[0022]
As described above, according to the present embodiment, the small abrasive layer portion 28 that is a grinding point for various grinding scraps such as the grinding scraps of the pad 4 and the solidified product of the slurry s, the wiring metal of the silicon wafer, and the silicon grinding scraps. It is possible to surely prevent clogging between the superabrasive grains 14... From the superabrasive grains 14. Moreover, it is possible to suppress the superabrasive grains 14 from being worn or worn by various grinding scraps by this grinding liquid, to promote the cooling of the superabrasive grains 14 and to suppress damage to the superabrasive grains 14.
Moreover, since the sum of the grinding lengths (sum of areas) of the abrasive layer 24 in the direction substantially parallel to the rotation direction P of the pad 4 is substantially equal, polishing with higher flatness can be performed.
[0023]
Next, a second embodiment of the present invention will be described with reference to FIG. 6, but the same or similar members as those in the first embodiment described above are denoted by the same reference numerals and the description thereof is omitted. FIG. 6 is a plan view of the main part of the wheel.
The wheel 40 shown in FIG. 6 has the same basic configuration as the wheel 20 according to the first embodiment. The difference is that the abrasive grain layer 42 forms a continuous spiral, and at least the abrasive grain layer. 42 is preferably wound in three or more layers at intervals in the radial direction (in FIG. 6, it is formed in three layers).
Also in this embodiment, the abrasive grain layer 42 is the outermost first abrasive grain layer 42A, the second abrasive grain layer 42B, and the innermost third abrasive grain when viewed as three layers from the radially outer side to the inner side. The layers 42C are continuously formed in a spiral shape so as to sequentially form the layers 42C. A spiral main discharge path 34 is formed between the respective abrasive grain layers 42A, 42B, and 42C, and each abrasive grain layer 42A, 42B, and 42C is provided with a large number of small abrasive grain layer portions 28 with a predetermined interval L. The sub discharge path 32 is formed in the gap.
Also in this embodiment, the same effect as the first embodiment can be obtained.
[0024]
Needless to say, the single-layer grindstone of the present invention can be used in a polishing grinding apparatus in addition to a conditioner used in a CMP apparatus.
[0025]
【The invention's effect】
As described above, in the single-layer grindstone according to the present invention, the abrasive layer is formed by arranging a plurality of small abrasive layer portions in which an opening for discharging a grinding liquid is formed in the approximate center. Grinding fluid can be supplied directly to the grinding point by the grains, and various grinding debris can be discharged without accumulating between the superabrasive grains. It can also be promoted.
[0026]
In addition, since the small abrasive layer portion is formed on the mound portion that protrudes at a predetermined interval on the base metal, even if the work material is a soft material such as a pad of a CMP apparatus, it is small and does not hit a solid surface. Since only the abrasive layer portion contacts and grinds the work material, the grinding pressure is high, the sharpness is good, and the grinding dust is discharged well.
In addition, since the discharge path is formed in an area other than the mound part, the supply source and the discharge path of the grinding fluid are arranged on both sides with the grinding point of the small abrasive layer part interposed therebetween. The distance can be shortened as much as possible, and the grinding fluid can reach the grinding point sufficiently, preventing the accumulation of grinding debris and washing away smoothly.
Moreover, since the diameter of the opening of the small abrasive layer portion is in the range of φ0.5 to 3.0 mm, the grinding scraps can be smoothly discharged without accumulating between the superabrasive grains, and the inner diameter of the opening is 0. If it is less than 5 mm, the grinding liquid cannot be sufficiently supplied to the grinding point, and if it exceeds 3.0 mm, the abundance ratio of the small abrasive grain layer portion decreases and the grinding ability decreases, which is not preferable.
Moreover, since the diameter of the mound part is 2 to 10 times the diameter of the opening, it is possible to prevent the grinding dust from accumulating at the grinding point and to wash away efficiently.
Since the height of the mound part with respect to the base metal is in the range of 0.1 to 5.0 mm, the grinding liquid and grinding waste can be easily discharged between the grinding point and the discharge path on the base metal.
[0027]
Since the distance between adjacent mound parts is in the range of 1/3 to 2 times the average diameter of the mound parts, the interval between the small abrasive layer parts can be set appropriately and the grinding pressure of superabrasive grains is kept high. In addition, various grinding scraps can be discharged smoothly with the grinding fluid.
Since the abrasive layer is formed in a plurality of ring-shaped or spiral shapes, the sum of the grinding lengths of the abrasive layer region in the direction substantially parallel to the relative movement direction of the work material is set in the movement direction of the work material. It can be made substantially uniform at an arbitrary position in a substantially orthogonal direction.
Since a discharge path is formed between the abrasive layers arranged at intervals in the radial direction, various grinding debris generated by grinding in the small abrasive layer portion is from the opening of the small abrasive layer portion. It is washed out together with the supplied grinding fluid and flows through the discharge path between the small abrasive layer parts, and is further discharged to the outside through the discharge path between the abrasive layer, so that the grinding waste can be easily discharged and the super abrasive grains It is possible to suppress the accumulation of deposits.
[Brief description of the drawings]
FIG. 1 is a plan view of a surface mounted with an abrasive layer of a wheel according to a first embodiment of the present invention.
FIG. 2 is a partially enlarged view of a second abrasive layer of the wheel shown in FIG.
FIG. 3 is a cross-sectional view of the wheel shown in FIG. 2 taken along the line BB.
FIGS. 4A, 4B, and 4C are views showing a manufacturing process of a wheel according to the first embodiment.
FIG. 5 is a diagram showing the relationship between the position of the abrasive grain layer in the rotational direction of the pad and the amount of work for the semicircular portion partitioned by the alternate long and short dash line of the wheel shown in FIG. 1;
FIG. 6 is a plan view of a wheel according to a second embodiment.
FIG. 7 is a perspective view of a main part of a conventional CMP apparatus.
8A and 8B show a conventional wheel used in the CMP apparatus shown in FIG. 7, in which FIG. 8A is a semicircular partial plan view of the wheel, and FIG. 8B is a longitudinal sectional view taken along line AA ′ of the wheel shown in FIG. FIG.
9 is an enlarged cross-sectional view of a main part showing an abrasive layer of the wheel shown in FIG.
[Explanation of symbols]
14 Superabrasive grains 20, 40 Wheel 22 Base metal 24, 42 Abrasive grain layers 24A, 42A First abrasive grain layers 24B, 42B Second abrasive grain layers 24C, 42C Third abrasive grain layer 25 Mound portion 26 Opening 28 Small abrasive grains Stratum 30 Waterway 32 Sub-discharge 34 Main discharge

Claims (9)

In a single-layer grindstone in which an abrasive layer in which superabrasive grains are fixed in a metal binder phase is mounted on a base metal, the abrasive layer is a small abrasive grain in which an opening for discharging a grinding liquid is formed at substantially the center. A plurality of layer portions are formed, and the small abrasive layer portion has a ring formed on the upper surface of a cylindrical mound portion having a circular cross section formed at the center and protruding on the base metal at a predetermined interval. A single-layer grindstone characterized in that the superabrasive grains are arranged in a single layer. The single-layer grindstone according to claim 1, wherein a discharge path is formed in an area other than the mound portion. The single-layer grindstone according to claim 1 or 2, wherein the opening of the small abrasive layer portion has a diameter in the range of 0.5 to 3.0 mm. The single-layer grindstone according to any one of claims 1 to 3 , wherein the diameter of the mound portion is 2 to 10 times the diameter of the opening. The single-layer grindstone according to any one of claims 1 to 4 , wherein a height of the mound portion with respect to the base metal is in a range of 0.1 to 5.0 mm. The single-layer grindstone according to any one of claims 1 to 5 , wherein the distance between the adjacent mound parts is in a range of 1/3 to 2 times the average diameter of the mound parts. The single-layer grindstone according to any one of claims 1 to 6 , wherein the abrasive grain layer is formed in a plurality of layers of a ring shape or a spiral shape. The single-layer grindstone according to claim 7 , wherein a discharge path is formed between the abrasive grain layers arranged at intervals in the radial direction. It is a manufacturing method of the single layer grindstone in any one of Claims 1 thru | or 8, Comprising: It discharges, discharging the plating solution containing the air or the said superabrasive grain from the said opening through the water flow path connected to the said opening of the said base metal. By performing the above, the superabrasive grains are fixed to the upper surface of the mound part with a metal binder phase.

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