JP7174517B2 - Polishing pad and polishing pad manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polishing pad and a method for manufacturing a polishing pad.

Polishing pads include hard polishing pads made of hard polyurethane resin and soft polishing pads made of soft polyurethane resin. A hard polishing pad is used for rough polishing and the like, and a soft polishing pad is used for finish polishing and the like.

On the other hand, a soft polishing pad is produced, for example, by a wet coagulation method (see, for example, Patent Document 2). For example, a substrate is coated with a viscous material obtained by dissolving a soft polyurethane resin in a polar solvent such as DMF (N,N-dimethylformamide), and the polar solvent is removed from the viscous material by bringing the viscous material into contact with water. This causes the resin to solidify on the substrate to form a soft polishing pad. In the polishing pad formed by such a method, teardrop-shaped voids are formed in the polyurethane resin because the polar solvent is replaced by water in the water bath.

JP 2012-101339 A

However, in a polishing pad manufactured by a wet coagulation method, due to the unique teardrop-shaped voids, the shape of the pores on the polishing surface expands over time as the polishing pad wears, and there is a risk that the polishing characteristics will change. be. Furthermore, the polishing rate is desired to be higher and more stable.

In view of the circumstances as described above, it is an object of the present invention to provide a polishing pad that suppresses changes in polishing characteristics due to wear of the polishing pad and that is stable at a high polishing rate.

In order to achieve the above object, a polishing pad according to one aspect of the present invention comprises a substrate and a polishing layer. The polishing layer contains a mixed polyurethane resin and hollow fine particles. The mixed polyurethane resin is coated onto the substrate. The mixed polyurethane resin includes a first polyurethane resin having a first 100% modulus value and a second polyurethane resin having a second 100% modulus value. The first 100% modulus value and the second 100% modulus value are 15.0 MPa or less. The second 100% modulus value is lower than the first 100% modulus value. A difference between the first 100% modulus value and the second 100% modulus value is 2.0 MPa or more. The hollow fine particles have an outer shell made of a thermoplastic resin and are dispersed in the mixed polyurethane resin.

With such a polishing pad, since hollow fine particles are added to a mixed polyurethane resin in which polyurethane resins having a low 100% modulus value and different 100% modulus values are mixed, the shape of the voids is controlled, and the polishing pad Abrasive properties are less likely to change with wear. Furthermore, the above polishing pad is improved in dressability by being mixed with a polyurethane resin, and stabilizes at a high polishing rate.

In the above polishing pad, the compression elastic modulus of the polishing layer may be 60.0% or more and 85.0% or less.

With such a polishing pad, the polishing pad has appropriate elasticity, and flatness is improved.

In the above polishing pad, the compressibility of the polishing layer may be 5.0% or less.

With such a polishing pad, the deformation of the polishing layer is suppressed, so that the polishing characteristics are less likely to change, the polishing object is not scratched, and the polishing rate is improved.

In the above polishing pad, the A hardness may be 50.0° or more and 90.0° or less.

With such a polishing pad, the polishing characteristics are less likely to change with the progress of polishing, the polishing target is not scratched, and the polishing rate is improved.

In the above polishing pad, the weight ratio of the first polyurethane resin and the second polyurethane resin may be in the range of 9:1 to 5:5.

With such a polishing pad, voids other than the hollow fine particles are less likely to occur in the polishing layer even when the thickness of the polishing layer is increased. Abrasive properties are less likely to change.

In the above polishing pad, the second 100% modulus value may be 2.0 MPa or more.

With such a polishing pad, voids other than the hollow fine particles are less likely to occur in the polishing layer, and the shape of the voids is controlled by the hollow fine particles.

To achieve the above object, a method for manufacturing a polishing pad according to one aspect of the present invention includes a first polyurethane resin having a first 100% modulus value and a second polyurethane resin having a second 100% modulus value. , the first 100% modulus value and the second 100% modulus value are 15.0 MPa or less, the second 100% modulus value is lower than the first 100% modulus value, and the first Prepare a mixed solution containing a mixed polyurethane resin in which the difference between the 100% modulus value of and the second 100% modulus value is 2.0 MPa or more, hollow fine particles having an outer shell made of a thermoplastic resin, and a solvent including doing The mixed solution is coated on the substrate. The solvent in the mixed solution is removed.

With the polishing pad manufactured by such a manufacturing method, hollow fine particles are added to a mixed polyurethane resin in which polyurethane resins having a low 100% modulus value and different 100% modulus values are mixed. is controlled, the dressing property is excellent, and the polishing properties hardly change with the wear of the polishing pad. Further, the above polishing pad does not scratch the object to be polished, and is improved in dressing property by being mixed with the polyurethane resin, and stabilizes at a high polishing rate.

In the polishing pad manufacturing method described above, the second 100% modulus value may be 2.0 MPa or more.

With a polishing pad manufactured by such a manufacturing method, voids are less likely to occur in the mixed polyurethane resin, and the shape of the voids is controlled by the hollow fine particles.

In the polishing pad manufacturing method described above, the weight ratio of the first polyurethane resin to the second polyurethane resin may be in the range of 9:1 to 5:5.

With a polishing pad manufactured by such a manufacturing method, voids other than the hollow fine particles are less likely to occur in the polishing layer, and the shape of the voids is controlled by the hollow fine particles, so that the polishing characteristics are less likely to change.

In the polishing pad manufacturing method described above, the mixed solution may be dried at a temperature of 35° C. or higher and 50° C. or lower.

As a result, a film is less likely to be formed on the surface of the mixed solution, and the solvent is efficiently volatilized from the mixed solution. As a result, voids other than the hollow fine particles are less likely to be formed, the shape of the voids is controlled by the hollow fine particles, and changes in polishing characteristics due to abrasion of the polishing pad can be prevented.

As described above, according to the present invention, it is possible to provide a polishing pad that suppresses changes in the polishing properties due to wear of the polishing pad and that is stable at a high polishing rate.

FIG. (a) is a schematic perspective view showing the configuration of the polishing pad 100 according to this embodiment. FIG. (b) is a schematic cross-sectional view of the polishing pad 100 according to this embodiment. FIG. (c) is a schematic cross-sectional view of the hollow fine particles 111 contained in the polishing pad 100 according to this embodiment. It is a schematic diagram which shows the manufacturing method of the polishing pad 100 which concerns on this embodiment. 4 is a table showing resin compounding ratios, physical property values, and evaluation results of the polishing layer 101. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Structure of Polishing Pad]

FIG. 1(a) is a schematic perspective view showing the configuration of a polishing pad 100 according to this embodiment. FIG. 1(b) is a schematic cross-sectional view of the polishing pad 100 according to this embodiment. FIG. 1(c) is a schematic cross-sectional view of hollow fine particles 111 contained in the polishing pad 100 according to this embodiment.

As shown in FIG. 1( a ), the polishing pad 100 comprises a polishing layer 101 and a base material 102 . The polishing layer 101 is a layer that contacts and polishes an object to be polished. The surface of the polishing layer 101 is referred to as a polishing surface 101a. The thickness of the polishing layer 101 is not particularly limited, but is preferably 0.3 mm or more and 2.0 mm or less, and can be, for example, 0.3 mm or more and 0.7 mm or less. The structure of the polishing layer 101 will be described later.

The polishing layer 101 is coated on the base material 102 for filling. A substrate 102 supports the polishing layer 101 . The base material 102 can be made of nonwoven fabric, but is not particularly limited, and preferably has cushioning properties. If the base material 102 is liquid-impregnable, such as a non-woven fabric, it may be coated with a binder to prevent the liquid from being impregnated.

Abrasive layer 101 is directly bonded to substrate 102 . No adhesive layer made of an adhesive or the like is provided between the polishing layer 101 and the base material 102 . Bonding of the polishing layer 101 and the substrate 102 can be achieved in the manufacturing process.

The polishing pad 100 is attached to a polishing machine via an adhesive tape or the like attached to the base material 102 and used for polishing. The size (diameter) of the polishing pad 100 can be determined according to the size of the polishing machine, etc. For example, the diameter can be 10 cm or more and 1 m or less. The shape of the polishing pad 100 is not limited to the disk shape shown in FIG. 1(a), and may be a belt shape that can be attached to the cylindrical surface of the roller. Note that the polishing pad 100 does not necessarily have to include the substrate 102 .

[Structure of Polishing Layer]
As shown in FIG. 1B, polishing layer 101 contains polyurethane resin 110 and hollow fine particles 111 .

Polyurethane resin 110 is a main constituent material of polishing layer 101 and is made of soft polyurethane resin.

The polyurethane resin 110 is a mixed polyurethane resin and includes a first polyurethane resin 110a and a second polyurethane resin 110b. Here, the polyurethane resin is, for example, a polyether polyester-based polyurethane resin. In this embodiment, mixed polyurethane resin may be simply referred to as polyurethane resin.

For each of the first polyurethane resin 110a and the second polyurethane resin 110b, a polyurethane resin soluble in an organic solvent can be used. As the first polyurethane resin 110a and the second polyurethane resin 110b, commercially available products such as PX-550 (manufactured by DIC Corporation) can be used.

The first polyurethane resin 110a has a first 100% modulus value. The second polyurethane resin 110b has a second 100% modulus value that is lower than the first 100% modulus value. Although FIG. 1B shows a state in which the second polyurethane resin 110b is dispersed in the first polyurethane resin 110a, this is a schematic diagram and the present invention is not limited to this example.

Here, the 100% modulus value is an index representing the hardness of the resin. The higher the 100% modulus value, the harder the resin, and the easier it is to scratch the object to be polished. On the other hand, the lower the 100% modulus value, the softer the resin.

In this embodiment, the first 100% modulus value and the second 100% modulus value are set to 15.0 MPa or less. The difference between the first 100% modulus value and the second 100% modulus value is 2.0 MPa or more. If the first 100% modulus value and the second 100% modulus value are larger than 15.0 MPa, the polishing layer 101 may scratch the object to be polished, which is undesirable. However, the second 100% modulus value is 2.0 MPa or more. The 100% modulus value is set by adjusting the ratio of the components contained in the polyurethane resin or the hard segment and the soft segment.

The weight ratio (ratio of parts by weight) of the first polyurethane resin 110a and the second polyurethane resin 110b is adjusted in the range of 9:1 to 5:5, more preferably 8:2 to 5:5. adjusted to range.

With such a weight ratio, the compression elastic modulus of the polishing layer 101 is adjusted to 60.0% or more and 85.0% or less. When the compression elastic modulus of the polishing layer 101 is 60.0% or more and 85.0% or less, the polishing pad as a whole has appropriate elasticity and the flatness is improved. Also, the compressibility of the polishing layer 101 is adjusted to 5.0% or less. When the compressibility of the polishing layer 101 is 5.0% or less, the deformation of the polishing pad is suppressed, the polishing characteristics are less likely to change, the polishing target is not scratched, and the polishing rate is improved. Also, the A hardness of the polishing pad 100 is adjusted to 50.0° or more and 90.0° or less. When the A hardness of the polishing pad 100 is 50.0° or more and 90.0° or less, the object to be polished is less likely to be scratched, and the polishing rate is improved.

In the polishing pad 100 having such characteristics, the polishing pad 100 does not scratch the object to be polished and improves the dressing property, thereby making it difficult for the pores of the polishing surface to become clogged, suppressing a decrease in the polishing rate, and improving the polishing rate. is maintained high.

The hollow fine particles 111 are dispersed in the polyurethane resin 110 (mixed polyurethane resin). FIG. 1(c) is a schematic cross-sectional view of the hollow fine particle 111. FIG. As shown in the figure, the hollow fine particle 111 has an outer shell 111a made of a thermoplastic resin and an internal space 111b surrounded by the outer shell 111a.

The hollow fine particles 111 can be formed by wrapping a liquid low-boiling-point hydrocarbon in a thermoplastic resin shell and heating the shell. The heating softens the thermoplastic resin, transforms the low-boiling-point hydrocarbon into a gas, and expands the thermoplastic resin due to the pressure of the gas, thereby forming the hollow fine particles 111 . Low boiling point hydrocarbons such as isobutane and pentane are used. The thermoplastic resin is preferably a synthetic resin that is insoluble or sparingly soluble in the solvent described later. ).MAN (methacrylonitrile) copolymers can be utilized.

Hollow fine particles 111 can also be commercially available. For example, 920DE40d30 (expancel series) can be used as the hollow fine particles 111 .

Although the size of the hollow fine particles 111 is not particularly limited, the diameter can be about 20 μm to 200 μm. The hollow fine particles 111 are exposed on the polishing surface 101a when the polishing layer 101 is worn by polishing, and affect the polishing characteristics of the polishing surface 101a. The density of the polishing layer 101 can be adjusted by the content ratio of the hollow fine particles 111 in the polishing layer 101 . The density of the polishing layer 101 is preferably 0.30 g/cm ³ or more and 0.60 g/cm ³ or less. When the density is within the above range, scratches due to clogging of the polished surface are less likely to occur.

In the polishing layer 101, spherical voids are present due to the hollow fine particles 111, and other voids (for example, voids due to foaming of the polyurethane resin, voids generated due to volatilization of the solvent, etc.) hardly exist. The voids other than the hollow fine particles are those having a major diameter larger than the diameter of the hollow fine particles (for example, larger than 200 μm), or having a hemispherical shape, a crushed spherical shape, an ellipsoidal shape, or the like. There is variation in the shape of the pods. If voids other than the hollow fine particles exist in the polishing layer 101, the shape of the voids in the thickness direction of the polishing layer 101 becomes uneven, which may change the polishing characteristics. On the other hand, since the shape of the hollow fine particles 111 is controlled, it is possible to prevent the polishing characteristics from changing due to abrasion of the polishing pad.

The thickness of the polishing layer 101 is preferably 0.3 mm or more and 2.0 mm or less. Since the thickness of the polishing layer 101 decreases with polishing, if the thickness of the polishing layer 101 is less than 0.3 mm, the life of the product will be shortened. On the other hand, if the thickness of the polishing layer 101 is more than 2.0 mm, the production efficiency of the polishing pad 100 is lowered and voids other than the hollow fine particles 111 are likely to occur in the polyurethane resin 110 . Therefore, the thickness of the polishing layer 101 is preferably 0.3 mm or more and 2.0 mm or less.

[Method for producing polishing pad]

Next, a method for manufacturing the polishing pad 100 will be described. 2(a) and 2(b) are schematic diagrams showing a method for manufacturing the polishing pad 100 according to this embodiment.

First, a resin solution in which the first polyurethane resin 110a is dissolved in a solvent and a resin solution in which the second polyurethane resin 110b is dissolved in a solvent are mixed to prepare a mixed solution S as shown in FIG. 2(a). . Mixed solution S contains resin solution R and hollow fine particles 111 .

The resin solution R contains a first polyurethane resin 110a, a second polyurethane resin 110b, and a solvent. Each of the first polyurethane resin 110a and the second polyurethane resin 110b is, for example, a polyether polyester-based polyurethane resin. In the resin solution R, the weight ratio of the first polyurethane resin 110a and the second polyurethane resin 110b is adjusted within the range of 9:1 to 5:5.

The solvent is a solvent capable of dissolving the mixed polyurethane resin, such as methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), tetrahydrofuran (THF), dimethyl Sulfoxide (DMSO), N-methylpyrrolidone (NMP), ethyl acetate, methyl acetate, ethanol, methanol, acetone, toluene, isopropyl alcohol (IPA), and the like. These solvents can be used as a single solvent or a mixed solvent. Furthermore, the resin solution may contain water for solubility adjustment. That is, the resin solution R is a liquid (or a viscous substance) in which a polyurethane resin is dissolved in a solvent (or a solvent and water).

The outer shell 111a of the hollow fine particles 111 can be made of a synthetic resin that is insoluble or sparingly soluble in the solvent. For example, when the solvent is a solvent containing any one of MEK, toluene, IPA, methyl acetate, ethyl acetate, methanol, and ethanol, the outer shell 111a is an MMA/AN/MAN copolymer that is sparingly soluble in these solvents. It can consist of

A mixed solution S can be obtained by adding the hollow fine particles 111 to the resin solution R and stirring the mixture. Subsequently, the mixed solution S is subjected to vacuum degassing or ultrasonic degassing.

Subsequently, as shown in FIG. 2B, the mixed solution S is coated on the base material 102 . A manufacturing apparatus 200 for manufacturing the polishing pad 100 includes a coater 201 and a dryer 202 . The coater 201 is arranged with a predetermined gap from the base material 102 delivered to the manufacturing apparatus 200 .

The base material 102 is sent out in the arrow direction in the drawing by a winding mechanism (not shown). Mixed solution S is coated on substrate 102 by coater 201 . The coater 201 is knife-shaped, and the thickness of the mixed solution S can be adjusted by adjusting the distance between the coater 201 and the substrate 102 . The base material 102 and the coated mixed solution S are passed through a dryer 202 to remove the solvent in the mixed solution S by drying, thereby forming the polishing layer 101 .

The drying temperature (air temperature in the drying space of the dryer 202) is preferably 35°C or higher and 50°C or lower, for example, 40°C. Drying time is 60 minutes.

For example, when the thickness of the polishing layer 101 is formed to be 0.3 mm or more by using a dry film-forming method that dries at a temperature higher than the boiling point of the solvent, a film is formed on the surface of the mixed solution R before the solvent is removed. is formed. Removal of the solvent is hindered by the film on the surface, and the solvent accumulates in a gaseous state in the polishing layer 101 to form voids. The voids other than the hollow fine particles have variations in size and shape, resulting in non-uniform voids in the polishing layer. As a result, the polishing characteristics become unstable, and a polishing pad having a polishing layer with a thickness of 0.3 mm or more cannot be obtained.

If the drying temperature is less than 35° C., it takes a long time (60 minutes or more) to remove the solvent, resulting in a decrease in production efficiency. On the other hand, if the drying temperature is higher than 50° C., a film is formed on the surface of the mixed solution S, and voids are formed in the mixed solution S by hindering volatilization of the solvent.

If voids are formed in the mixed solution S during drying, voids other than the hollow fine particles 111 will be generated in the polishing layer 101 . Since the voids are non-uniform in shape, the distribution of the voids in the polishing layer 101 becomes non-uniform, resulting in changes in polishing characteristics due to abrasion of the polishing pad. Therefore, the drying temperature of the mixed solution is preferably 35°C or higher and 50°C or lower. A gel permeation chromatography (GPC) measurement was performed on the polishing layer 101, which was obtained by mixing a plurality of polyurethane resins and drying and solidifying them. By analyzing the obtained molecular weight distribution, it was determined that a plurality of polyurethane resins were mixed to form the polishing layer 101. can. A polishing layer using one polyurethane resin and a polishing layer containing a mixture of a plurality of polyurethane resins are each dissolved in DMF to prepare a sample solution, the sample solution is measured by GPC, and the obtained molecular weight distributions are compared. distinguishes them.

A sheet in which the base material 102 and the polishing layer 101 are laminated is cut into a predetermined shape to manufacture the polishing pad 100 .

In the wet process, which is generally used as a method for producing soft polyurethane polishing pads, a polyurethane solution is coated on a support, solidified in a water bath, passed through a solvent removing bath, and dried.

In the wet method, dimethylformamide (DMF) is used as a solvent for polyurethane resin, but hollow fine particles that are insoluble in DMF have a thick outer shell, and tear-shaped foaming is likely to occur in the polyurethane resin, resulting in an unstable polishing rate. .

On the other hand, the outer shell 111a of the hollow fine particles 111 of this embodiment is made of a synthetic resin that is insoluble or sparingly soluble in the solvent of the polyurethane resin. By forming the outer shell 111a of the hollow fine particles 111 from a thermoplastic resin that is insoluble or sparingly soluble in the solvent of the polyurethane resin, it is possible to control the shape of the voids without causing tear-shaped foaming. Furthermore, according to this embodiment, the manufacturing process can be simplified compared to the wet method.

In the polishing pad 100 manufactured by such a manufacturing method, the hollow fine particles 111 are added to the mixed polyurethane resin 110 in which the polyurethane resins 110a and 110b having a low 100% modulus value and different 100% modulus values are mixed. be. As a result, the shape of the voids is controlled by the hollow fine particles, and the polishing characteristics are less likely to change with wear of the polishing pad. Furthermore, the polishing pad 100 does not scratch the object to be polished, and is mixed with polyurethane resin to improve the dressing properties, so that the pores of the polishing surface are less likely to be clogged, and the polishing rate is maintained in a high state. .

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the present embodiment is not limited to these Examples and the like.

FIG. 3 is a table showing the resin compounding ratio, physical property values, and evaluation results of the polishing layer 101. As shown in FIG.

In FIG. 3, the 100% modulus value, thickness, density, compressibility, compression modulus, A hardness, polishing rate, Taber abrasion amount and air generation are obtained as follows.

(100% modulus value)
A non-foamed resin sheet is used as a test piece, and the test piece (non-foamed polyurethane) is stretched 100% in an environment of room temperature 23 ± 2 ° C., that is, when stretched to twice its original length. The value obtained by dividing the tensile stress by the initial cross-sectional area of the test piece was taken as the 100% modulus value.

(Thickness of polishing layer)
The thickness of the polishing layer was measured from the image obtained by imaging the cross section of the polishing layer with a CCD. In addition, the thickness of the substrate was measured in the same manner.

(Density of polishing layer)
A sample piece (10 cm x 10 cm) was cut out from the polishing layer, and its mass W0 (g) was measured with an electronic balance (model Metra-AJ-180). It was calculated from the measured thickness t (cm) and mass W0 (g) by density (ρ)=W0/t/100 (g/cm ³ ).

(Compressibility and compression modulus)
The compressibility and compressive modulus were determined according to Japanese Industrial Standard JIS L 1021. Specifically, the thickness _t0 after applying the initial load for 30 seconds from the no-load state at room temperature is measured, and then the thickness t after applying the final load for 5 minutes from the thickness _t0 state. ₁ was measured. Next, all the load was removed from the state of the thickness t ₁ , and the thickness t ₀ ′ was measured after the initial load was applied again for 30 seconds after being left for 5 minutes (to be in a no-load state).

The compressibility is calculated by the formula of compression rate (%) = 100 x (t ₀ - t ₁ )/t ₀ , and the compression modulus is calculated as compression modulus (%) = 100 x (t ₀ '-t ₁ ). /(t ₀ -t ₁ ). At this time, the initial load was 100 g/cm ₂ and the final pressure was 1120 g/cm ₂ .

(A hardness)
The A hardness of the polishing pad was determined according to Japanese Industrial Standard JIS K 7311. A sample piece (10 cm x 10 cm) was cut out from the polishing pad, and a plurality of sample pieces were stacked so as to have a total thickness of 4.5 mm or more, and the hardness was measured using an A-type hardness tester.

(polishing rate)
The polishing pad was subjected to polishing processing under the following polishing conditions, and the polishing rate was measured. In the measurement, a polishing pad was attached to a predetermined position of a polishing machine, and a silicon wafer with a TEOS film was used as a work (object to be polished). The polishing rate is obtained by dividing the amount of polishing, which is the difference in the thickness of the TEOS film before and after the polishing of 25 wafers, by the polishing time. asked. The thickness was measured by using an optical film thickness measuring device (manufactured by KLA-Tencor, trade name "ASET-F5x", measurement: DBS mode) to measure the polishing rate (before polishing). The surface of the polishing pad was dressed in advance using a dresser under the following dressing conditions: pressure of 30 N, rotational speed of the polishing head and polishing platen of 54 rpm, supply of ultrapure water of 200 mL/min, and dressing time of 30 seconds. used for measurement. Using this polishing pad, the polishing rate (after polishing) was measured in the same manner as described above. The measurement results are shown in FIG.

<Polishing conditions>
Polishing machine used: Ebara Corporation, trade name "F-REX300"
Polishing speed (surface plate rotation speed): 70 rpm
Polishing head rotation speed: 71 rpm
Processing pressure: 2.5 psi
Abrasive: Colloidal silica slurry (undiluted solution: pure water = 1:1 weight ratio mixed solution is used)
Abrasive flow rate: 200 mL/min
Polishing time: 60 seconds Object to be polished: Silicon wafer (12 inches) with TEOS (Tetra Ethyl Ortho Silicate)

(Taber wear amount)
It was measured according to the Taber abrasion test of Japanese Industrial Standards (JIS K 6902). The wear tester has a rotating disc that is journalled so as to be rotatably driven. A pair of cylindrical wear wheels are arranged above the rotating disc with their end faces facing each other. The outer peripheral surface of the wear wheel is arranged so as to be able to come into contact with the sample attached to the rotating disk. The wear wheels are arranged on both radial sides of the wheel, equidistant from the axis of rotation of the wheel. Abrasive paper is pasted on the outer periphery of the wear wheel so that no gaps are formed and the abrasive papers do not overlap each other. When measuring the amount of wear, a sample (polishing layer) cut into the same shape as the rotating disk is attached to the rotating disk. A wear wheel with abrasive paper attached is brought into contact with the upper surface of the sample, and pressed so that the load applied to the contact surface is 5.20±0.2N. By rotating the rotating disk, a pair of wear wheels whose outer peripheral surfaces are in contact with the sample rotate in opposite directions. In the measurement of the amount of wear, the surface of the polishing layer (polishing surface) was brought into contact with an abrasion wheel with 320-grit sandpaper attached to the outer circumference, and the surface of the polishing layer (polishing surface) was rotated at 1000 revolutions. The wear amount (mg) per time was measured.

(air generation)
The presence or absence of air generation (occurrence of voids other than hollow fine particles) was determined by exposing the polished surface to light and visually confirming the presence or absence of bulges on the polished surface. In addition, a portion where swelling was confirmed on the polished surface was confirmed by observing a cross section of the polished layer with an electron microscope (CCD or SEM) at a magnification of 50 times.

In Examples 1 to 3, a polyether polyester-based polyurethane resin having a 100% modulus value of 9.0 MPa was used as the first polyurethane resin 110a, and a polyether polyester having a 100% modulus value of 2.1 MPa was used as the second polyurethane resin 110b. system polyurethane resin was used. In the examples and comparative examples, a solution containing 30 parts of a polyurethane resin and 70 parts of a solvent was used as the polyurethane resin.

(Example 1)

80 parts by weight of a polyether polyester-based polyurethane resin solution with a 100% modulus value of 9.0 MPa, 20 parts by weight of a polyether polyester-based polyurethane resin solution with a 100% modulus value of 2.1 MPa, 0.7 parts of hollow fine particles, and 2.5 parts of a solvent was prepared. Next, after the polyurethane mixed solution was coated on the base material 102 having a thickness of 1.81 mm by the coater 201, the solvent in the polyurethane mixed solution was dried by the dryer 202 to prepare the polishing layer.

In Example 1, the compressibility of the polishing layer was 4.2%, the compression modulus was 73.3%, and the A hardness of the polishing pad was 61.0 degrees. The polishing rate of the polishing layer was 100 nm, and the amount of Taber abrasion was 240 mg. Also, no air was generated in the polishing layer. Furthermore, no scratches occurred on the object to be polished.

(Example 2)

Example 1 except that the polyether polyester-based polyurethane resin solution with a 100% modulus value of 9.0 MPa was set to 60 parts by weight and the polyether polyester-based polyurethane resin solution with a 100% modulus value of 2.1 MPa was set to 40 parts by weight. A polishing layer was prepared in the same manner.

In Example 2, the compressibility of the polishing layer was 3.9%, the compression modulus was 71.8%, and the A hardness of the polishing pad was 64.0 degrees. The polishing rate of the polishing layer was 120 nm, and the amount of Taber abrasion was 243 mg. Also, no air was generated in the polishing layer. Furthermore, no scratches occurred on the object to be polished.

In Example 2, although the weight part of the polyether polyester polyurethane resin solution with a 100% modulus value of 9.0 MPa was set lower than in Example 1, the polishing rate was higher than in Example 1.

(Example 3)

Example 1, except that the polyether polyester-based polyurethane resin solution with a 100% modulus value of 9.0 MPa was set to 50 parts by weight and the polyether polyester-based polyurethane resin solution with a 100% modulus value of 2.1 MPa was set to 50 parts by weight. A polishing layer was prepared in the same manner.

In Example 3, the compressibility of the polishing layer was 4.0%, the compression modulus was 77.9%, and the A hardness of the polishing pad was 60.0 degrees. The polishing rate of the polishing layer was 100 nm, and the Taber abrasion amount was 235 mg. Also, no air was generated in the polishing layer. Furthermore, no scratches occurred on the object to be polished.

(Comparative example 1)

A polishing layer was prepared in the same manner as in Example 1, except that the polyether polyester polyurethane resin solution with a 100% modulus value of 9.0 MPa was 100 parts by weight and the solvent was 5 parts by weight.

In Comparative Example 1, the compressibility of the polishing layer was 8.0%, the compression modulus was 91.7%, and the A hardness of the polishing pad was 59.5 degrees. The polishing rate of the polishing layer was 75 nm, and the Taber abrasion amount was 206 mg. Also, no air was generated in the polishing layer.

(Comparative example 2)

Example 1, except that the polyether polyester-based polyurethane resin solution with a 100% modulus value of 9.0 MPa was set to 40 parts by weight and the polyether polyester-based polyurethane resin solution with a 100% modulus value of 2.1 MPa was set to 60 parts by weight. A polishing layer was prepared in the same manner.

In Comparative Example 2, air was generated in the polishing layer, and the compressibility, compression modulus, A hardness, polishing rate, and Taber abrasion amount could not be measured.

(Comparative Example 3)

A polishing layer was prepared in the same manner as in Example 1, except that the polyether polyester polyurethane resin solution having a 100% modulus value of 5.9 MPa was set to 100 parts by weight.

In Comparative Example 3, the compressibility of the polishing layer was 5.5%, the compression modulus was 94.5%, and the A hardness of the polishing pad was 61.0 degrees. The polishing rate of the polishing layer was 70 nm, and the Taber abrasion amount was 193 mg. Also, no air was generated in the polishing layer.

In Comparative Example 1, the polyether polyester polyurethane resin solution with a 100% modulus value of 9.0 MPa was adjusted to 100 weight, and the 100% modulus value of the polishing layer was set higher than in Examples 1 to 3. , the polishing rate was lower than in Examples 1-3. Also, the amount of Taber wear was smaller than in Examples 1-3.

Further, as shown in Comparative Example 2, the weight part of the polyether polyester polyurethane resin solution with a 100% modulus value of 2.1 MPa is higher than the weight part of the polyether polyester polyurethane resin solution with a 100% modulus value of 9.0 MPa. It has been found that if the adjustment is made so that the polishing layer becomes too soft and air is generated, uniform polishing characteristics cannot be obtained.

Further, in Comparative Example 3, the polyether polyester polyurethane resin solution having a 100% modulus value of 5.9 MPa was adjusted to 100 parts by weight, and the 100% modulus value of the polishing layer was adjusted to about Examples 1 to 3. Regardless, the polishing rate decreased compared to Examples 1-3. Also, the amount of Taber wear was smaller than in Examples 1-3.

In other words, in Examples 1 to 3, in addition to the polyether polyester-based polyurethane resin with a 100% modulus value of 9.0 MPa, the polyether polyester-based polyurethane resin with a 100% modulus value of 2.1 MPa was mixed in the polishing layer. As a result, compared to Comparative Examples 1 and 3, the compressibility and compression elastic modulus are relatively decreased, and the polishing rate and Taber wear amount are increased compared to Comparative Examples 1 and 3.

That is, as in this example, by mixing two polyether polyester-based polyurethane resins having a 100% modulus value of 15.0 MPa or less and a difference in 100% modulus value of 2.0 MPa or more, the polishing layer , the dressability is improved, the openings of the polishing surface are less likely to be clogged, and the decrease in the polishing rate is suppressed.

When the proportion of polyether polyester polyurethane resin with a low 100% modulus value is increased, the polishing layer becomes too soft and tends to generate air. Therefore, the 100% modulus value of the second polyurethane resin 110b may be adjusted to, for example, 2.0 MPa or more.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments and can be modified in various ways. Each embodiment is not limited to an independent form, and can be combined as much as technically possible.

DESCRIPTION OF SYMBOLS 100... Polishing pad 101... Polishing layer 101a... Polishing surface 102... Base material 110... Polyurethane resin (mixed polyurethane resin)
DESCRIPTION OF SYMBOLS 110a... 1st polyurethane resin 110b... 2nd polyurethane resin 111... Hollow microparticles|fine-particles 111a... Outer shell 111b... Internal space 200... Manufacturing apparatus 201... Coater 202... Dryer

Claims (8)

a substrate;
coated on the substrate,
a first polyurethane resin having a first 100% modulus value and a second polyurethane resin dispersed in said first polyurethane resin and having a second 100% modulus value, said first polyurethane resin and said second polyurethane resin The weight ratio with the resin is 9:1 to 5:5, the first 100% modulus value and the second 100% modulus value are 15.0 MPa or less, and the second 100% modulus value is Lower than the first 100% modulus value, a difference between the first 100% modulus value and the second 100% modulus value is 2.0 MPa or more, and is lower than the first 100% modulus value a non-foaming mixed polyurethane resin having a low 100% modulus value;
A polishing pad comprising: a polishing layer comprising hollow fine particles having an outer shell made of a thermoplastic resin and dispersed in the mixed polyurethane resin; The polishing pad according to claim 1,
The polishing pad, wherein the compression elastic modulus of the polishing layer is 60.0% or more and 85.0% or less. The polishing pad according to claim 1 or 2,
The polishing pad, wherein the compressibility of the polishing layer is 5.0% or less. The polishing pad according to any one of claims 1 to 3,
The polishing pad has an A hardness of 50.0° or more and 90.0° or less. The polishing pad according to any one of claims 1 to 4,
The polishing pad, wherein the second 100% modulus value is 2.0 MPa or more. a first polyurethane resin having a first 100% modulus value and a second polyurethane resin dispersed in said first polyurethane resin and having a second 100% modulus value, said first polyurethane resin and said second polyurethane resin The weight ratio with the resin is 9:1 to 5:5, the first 100% modulus value and the second 100% modulus value are 15.0 MPa or less, and the second 100% modulus value is Lower than the first 100% modulus value, a difference between the first 100% modulus value and the second 100% modulus value is 2.0 MPa or more, and is lower than the first 100% modulus value preparing a mixed solution containing a mixed polyurethane resin having a low 100% modulus value and no foaming, hollow fine particles having an outer shell made of a thermoplastic resin, and a solvent;
Coating the mixed solution on a substrate,
A method for producing a polishing pad , wherein a polishing layer in which the hollow fine particles are dispersed in the mixed polyurethane resin is formed on the substrate by removing the solvent in the mixed solution by volatilizing it . A method for manufacturing a polishing pad according to claim 6,
The method for manufacturing a polishing pad, wherein the second 100% modulus value is 2.0 MPa or more. A method for manufacturing a polishing pad according to claim 6 or 7,
A method for manufacturing a polishing pad, wherein the mixed solution is dried at a temperature of 35°C or higher and 50°C or lower.

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