Abrasive pads and methods for manufacturing abrasive pads

Abstract

A polishing pad and a method for manufacturing the polishing pad, comprising a polishing layer including a polyurethane resin foam, the polyurethane resin foam including an isocyanate-terminated prepolymer and a curing agent, wherein the weight ratio (NC80) of the amorphous phase in the polishing layer, as determined by pulse NMR at 80°C, to the weight ratio (NC40) of the amorphous phase in the polishing layer, as determined by pulse NMR at 40°C, is 1.5 to 2.5 (NC80 / NC40).

Description

Technical Field

[0001] This invention relates to an polishing pad. The polishing pad of this invention is used for polishing optical materials, semiconductor components, glass substrates for hard disks, etc., and is particularly suitable for polishing components on semiconductor wafers having oxide layers, metal layers, etc. Especially relevant is an polishing pad and a method for manufacturing the polishing pad. Background Technology

[0002] Chemical mechanical polishing (CMP) is a commonly used polishing method for planarizing the surfaces of optical materials, semiconductor wafers, semiconductor components, and hard disk substrates.

[0003] use Figure 1 The CMP method will be explained. For example... Figure 1 Thus, the grinding apparatus 1 for performing the CMP method includes a grinding pad 3, which is held in place by a retaining ring in a manner that prevents the pressure plate 16 and the workpiece 8 from shifting. Figure 1 The grinding pad 3 (not shown) abuts against the workpiece 8 and includes a grinding layer 4 as the grinding layer and a buffer layer 6 supporting the grinding layer 4. The grinding pad 3 is rotated while the workpiece 8 is pressed, thereby grinding the workpiece 8. At this time, a slurry 9 is supplied between the grinding pad 3 and the workpiece 8. The slurry 9 is a mixture (dispersion) of water and various chemical components or hard, fine abrasive particles. The grinding effect is enhanced by the relative movement between the chemical components or abrasive particles and the workpiece 8 while the slurry flows. The slurry 9 is supplied to the grinding surface through a groove or hole and then discharged.

[0004] Furthermore, the polishing layer material used in the polishing of semiconductor components is a rigid polyurethane material. This rigid polyurethane material is obtained by reacting a prepolymer containing isocyanate components (such as toluene diisocyanate (TDI)) and high molecular weight polyols (such as polyoxytetramethylene glycol (PTMG)) with a diamine-based curing agent (such as 4,4'-methylenebis(2-chloroaniline) (3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA)). The rigid polyurethane material comprises soft segments formed from high molecular weight polyols and hard segments formed from urethane bonds or urea bonds. In recent years, with the miniaturization of semiconductor device wiring, the polishing rate or defect performance (scratch, etc.) in previous polishing layers or pads is sometimes insufficient, and further research is being conducted.

[0005] Patent Document 1 discloses an abrasive pad in which the abrasive layer contains more than 70% of a crystalline phase (S phase) obtained by pulsed nuclear magnetic resonance (NMR) method, resulting in less hardness change caused by heat, and thus enabling thorough abrasion, scratch resistance, and stable abrasion performance.

[0006] However, a study of Patent Document 1 revealed that scratches are easily generated only when the crystalline phase content exceeds 70% at room temperature. The reason for this is that when foreign matter is mixed in during grinding, the temperature rises due to the foreign matter, thereby changing the proportions of the crystalline phase, intermediate phase, and amorphous phase, and sometimes altering the characteristics of the grinding layer.

[0007] In addition, from the point of view of durability, the abrasive pad is preferably hard, but if it is too hard, it will not eliminate the unevenness (step performance) on the object being abraded, and the undesirable situation will occur that even if abrasion is continued, the step difference will not be eliminated at all.

[0008] In rigid polyurethane materials, research has been conducted on using components other than PTMG as high molecular weight polyols in order to eliminate insufficient grinding speed or defect performance.

[0009] Patent document 2 discloses an abrasive pad in which a high molecular weight polyol with polypropylene glycol (PPG) as a prepolymer is used, resulting in high step elimination performance and few scratches.

[0010] In addition, Patent Document 3 discloses an abrasive pad in which a high molecular weight polyol, using a mixture of PPG and PTMG as a prepolymer, reduces the defect rate.

[0011] However, the abrasive pad described in Patent Document 2 has problems such as poor wear resistance of the abrasive layer, short lifespan of the abrasive pad, and insufficient abrasive rate. In addition, the abrasive pad described in Patent Document 3 has the problem of insufficient performance due to the presence of PTMG.

[0012] Moreover, in order to achieve a high grinding rate, the grinding pad usually needs to be set to high hardness. High-hardness grinding pads also have poor imperfection performance (scratch performance). There is a trade-off between grinding rate and imperfection performance.

[0013] [Existing Technical Documents]

[0014] [Patent Literature]

[0015] Patent Document 1: Japanese Patent Re-registration No. 2016 / 158348

[0016] Patent Document 2: Japanese Patent Application Publication No. 2020-157415

[0017] Patent Document 3: Japanese Patent Application Publication No. 2011-040737 Summary of the Invention

[0018] [The problem the invention aims to solve]

[0019] The present invention is made in view of the aforementioned problems, and aims to provide a grinding pad with excellent step difference elimination performance, high grinding rate, excellent defect performance, and thus excellent wear resistance.

[0020] The inventors studied the proportions of crystalline phase, intermediate phase, and amorphous phase in the polishing layer and found that when the weight ratio of the amorphous phase at 40°C and the weight ratio of the amorphous phase at 80°C are within a specified range, a polishing pad with a polishing layer that is difficult to scratch and has excellent step elimination performance can be obtained.

[0021] Furthermore, it was discovered that by setting the polyol used as the material of the abrasive layer in the abrasive pad to a specific polyol, abrasive pads that achieve high abrasive rates, excellent defect performance, and excellent wear resistance can be produced.

[0022] That is, the present invention includes the following.

[0023] [Technical means to solve the problem]

[0024] [1] An abrasive pad having an abrasive layer comprising a polyurethane resin foam, said polyurethane resin foam being derived from an isocyanate-terminated prepolymer and a hardener, wherein the abrasive pad contains...

[0025] The ratio (NC80 / NC40) of the weight percentage of the amorphous phase in the polished layer as determined by pulsed NMR at 80°C (NC80) to the weight percentage of the amorphous phase in the polished layer as determined by pulsed NMR at 40°C (NC40) is 1.5 to 2.5.

[0026] [2] According to the polishing pad described in [1], the value obtained by the following formula (1) is 1.20 to 1.50, wherein the weight ratio of the amorphous phase and the crystalline phase in the polishing layer is determined by pulse NMR at 40°C and 80°C.

[0027] [Formula 1]

[0028]

[0029] [3] The abrasive pad according to [1] or [2], wherein the NC40 is 10% to 20% by weight.

[0030] [4] The abrasive pad according to any one of [1] to [3], wherein the NC80 is 25% to 35% by weight.

[0031] [5] The abrasive pad according to any one of [1] to [4], wherein the abrasive layer comprises polypropylene glycol and polyether polycarbonate diol.

[0032] [6] According to the abrasive pad of [5], the proportion of the polyether polycarbonate diol to the total of the polypropylene glycol and the polyether polycarbonate diol is less than 80%.

[0033] [7] An abrasive pad having an abrasive layer comprising a polyurethane resin foam derived from an isocyanate-terminated prepolymer and a hardener, wherein the abrasive pad contains...

[0034] The value obtained by the following formula (2) is 0.70 to 1.30, where the weight ratio of the amorphous phase and the crystalline phase in the polishing layer is determined by pulse NMR at 40°C and 80°C.

[0035] [Formula 2]

[0036]

[0037] [8] According to the abrasive pad described in [7], the difference between the maximum and minimum values ​​of tanδ obtained by measuring the abrasive layer using a dynamic viscoelasticity test at 40°C to 80°C is less than 0.030.

[0038] [9] The abrasive pad according to [7] or [8], wherein the NC40 is 10% to 20% by weight.

[0039]

[10] The abrasive pad according to any one of [7] to [9], wherein the NC80 is 25% to 35% by weight.

[0040]

[11] The abrasive pad according to any one of [7] to

[10] , wherein the abrasive layer comprises polypropylene glycol and polyether polycarbonate diol.

[0041]

[12] The abrasive pad according to

[11] , wherein the polyether polycarbonate diol is in a ratio of less than 80% to the total of the polypropylene glycol and the polyether polycarbonate diol.

[0042]

[13] An abrasive pad having an abrasive layer comprising a polyurethane resin foam derived from an isocyanate-terminated prepolymer and a hardener, wherein the abrasive pad contains...

[0043] The isocyanate-terminated prepolymer comprises structural units derived from polyisocyanate compounds and structural units derived from high molecular weight polyols.

[0044] The structural units derived from high molecular weight polyols include at least polypropylene glycol structural units and polyether polycarbonate diol structural units.

[0045] The polypropylene glycol structural unit is less than 80% by weight relative to the structural unit derived from the high molecular weight polyol.

[0046]

[14] The abrasive pad according to

[13] , wherein the polypropylene glycol structural unit is 30% to 70% by weight relative to the structural unit derived from the high molecular weight polyol.

[0047]

[15] The abrasive pad according to

[13] or

[14] , wherein the polyether polycarbonate diol structural unit is derived from polyether polycarbonate diol having a number average molecular weight of 600 to 2500.

[0048]

[16] A method for manufacturing an abrasive pad, comprising manufacturing an abrasive pad having an abrasive layer comprising a polyurethane resin foam, the method comprising:

[0049] A process of reacting a polyisocyanate compound with a high molecular weight polyol comprising at least polypropylene glycol and polyether polycarbonate diol to obtain an isocyanate-terminated prepolymer.

[0050] The process of reacting the isocyanate-terminated prepolymer with a curing agent to obtain the polyurethane resin foam; and

[0051] The process of molding the polyurethane resin foam and forming it into the shape of a polished layer, and

[0052] The polypropylene glycol is less than 80% by weight relative to the total amount of the high molecular weight polyols.

[0053] [The effects of the invention]

[0054] The abrasive pad of the present invention has excellent defect performance, as well as excellent step elimination performance and abrasive rate.

[0055] Furthermore, according to the present invention, by using a high molecular weight polyol containing polypropylene glycol and polyether polycarbonate diol as the material of the abrasive layer, an abrasive pad that achieves high abrasive rate, excellent defect performance, and excellent wear resistance can be obtained. Attached Figure Description

[0056] Figure 1 This is a schematic diagram illustrating the state of grinding using a grinding pad.

[0057] Figure 2 These are schematic diagrams and cross-sectional views of the abrasive pad.

[0058] Figure 3 This is a graph illustrating the performance of step elimination.

[0059] Figure 4 The results of the step elimination performance test of the examples and comparative examples are shown (for the polished objects using Cu wiring with a width of 120 μm).

[0060] Figure 5 The results of the step elimination performance test of the examples and comparative examples are shown (the case of the polished object with a wire width of 100 μm relative to the Cu wire width of 100 μm).

[0061] Figure 6 The results of the step elimination performance test of the examples and comparative examples are shown (the case of the polished object with a wire width of 50 μm relative to the Cu wire width of 50 μm).

[0062] Figure 7The results of the step elimination performance test of the examples and comparative examples are shown (the case of the polished object with a wire width of 10 μm relative to the Cu wire width of 10 μm).

[0063] Figure 8 This indicates the results of the defect performance evaluation tests for the embodiments and comparative examples.

[0064] Figure 9 This is the result of tanδ obtained in Example 6.

[0065] Figure 10 This is the result of tanδ obtained in Comparative Example 2.

[0066] Figure 11 This is a graph showing the step elimination performance of the embodiments and comparative examples (using a polished object with a wire width of 100 μm relative to the Cu wire width of 100 μm).

[0067] Figure 12 This is a graph showing the step difference elimination performance of the embodiments and comparative examples (using a polished object with a wire width of 50 μm relative to the Cu wire width of 50 μm).

[0068] Figure 13 This is a graph showing the changes in wear (thickness) of the abrasive pads in the embodiments and comparative examples.

[0069] Figure 14 This is a graph showing the evaluation results of the grinding rate of the grinding pads of the embodiments and comparative examples.

[0070] Figure 15 These are the results of grinding tests on the defective properties of the examples and comparative examples.

[0071] Explanation of reference numerals in the attached figures

[0072] 1: Grinding device

[0073] 3: Grinding pad

[0074] 4: Grinding layer

[0075] 4A: Hollow microspheres

[0076] 6: Buffer layer

[0077] 7: Next layer

[0078] 8: The material being ground

[0079] 9: Slurry

[0080] 10: Grinding and pressing plate Detailed Implementation

[0081] The following describes the methods for carrying out the invention, but the invention is not limited to these methods.

[0082] <<Abrasive Pad>>

[0083] use Figure 2 Explain the structure of abrasive pad 3. For example... Figure 2 Thus, the abrasive pad 3 includes an abrasive layer 4 and a buffer layer 6. The shape of the abrasive pad 3 is preferably disc-shaped, but there is no particular limitation. In addition, the size (diameter) can be appropriately determined according to the size of the abrasive device 1 including the abrasive pad 3, for example, it can be set to a diameter of about 10cm to 2m.

[0084] Furthermore, the abrasive pad 3 of the present invention is preferably as follows: Figure 2 As shown, the polishing layer 4 is attached to the buffer layer 6 via the bonding layer 7.

[0085] The abrasive pad 3 is attached to the abrasive pressure plate 10 of the abrasive device 1 via double-sided adhesive tape or the like, which is disposed on the buffer layer 6. The abrasive pad 3 is driven to rotate by the abrasive device 1 while pressing the workpiece 8, thereby abrading the workpiece 8.

[0086] <Abrasive Layer>

[0087] (structure)

[0088] The abrasive pad 3 includes an abrasive layer 4, which serves as a layer for abrading the workpiece 8. The abrasive layer 4 is made of polyurethane foam. The material and manufacturing method of the polyurethane foam will be described later.

[0089] The size (diameter) of the polishing layer 4 is the same as that of the polishing pad 3, which can be set to a diameter of about 10cm to 2m. The thickness of the polishing layer 4 can usually be set to about 1mm to 5mm.

[0090] The grinding layer 4 rotates together with the grinding pressure plate 10 of the grinding device 1. While the slurry 9 flows on it, the chemical components or grinding particles contained in the slurry 9 move relative to the workpiece 8 being ground, thereby grinding the workpiece 8.

[0091] like Figure 2 In this way, hollow microspheres 4A are dispersed in the grinding layer 4. When the grinding layer 4 is worn down, the hollow microspheres 4A are exposed to the grinding surface and create tiny gaps on the grinding surface. These tiny gaps hold the slurry, thereby allowing for further grinding of the workpiece 8.

[0092] In addition, the abrasive layer 4 is preferably formed by dry molding.

[0093] (groove machining)

[0094] Preferably, grooves are provided on the surface of the grinding layer 4 on the side of the workpiece 8, as needed. The grooves are not particularly limited and can be either a slurry discharge groove communicating with the periphery of the grinding layer 4 or a slurry retention groove not communicating with the periphery of the grinding layer 4. Alternatively, both a slurry discharge groove and a slurry retention groove may be provided. Examples of slurry discharge grooves include grid-shaped grooves and radial grooves; examples of slurry retention grooves include concentric circular grooves and perforations (through holes), and combinations of these may also be used.

[0095] (Shaw D hardness)

[0096] The Shore D hardness of the abrasive layer 4 of the present invention is not particularly limited, for example, it is 20 to 100, preferably 30 to 80, and even more preferably 40 to 70. When the Shore D hardness is low, it is difficult to flatten the fine unevenness by low-pressure grinding. If the Shore D hardness is too high, the workpiece 8 may be subjected to strong friction, resulting in scratches on the processed surface of the workpiece 8.

[0097] In the abrasive pad 3 of the present invention, hollow microspheres 4A are used to encapsulate air bubbles inside the polyurethane resin molded body. A hollow microsphere is a microsphere having pores. The shape of the hollow microspheres 4A includes spherical, elliptical, and similar shapes. Further explanation of the hollow microspheres is provided in the section on the manufacturing method.

[0098] (Crystalline phase, mesophase, amorphous phase)

[0099] In the polishing layer of the polishing pad according to one embodiment of the present invention, the ratio (sometimes expressed as NC80 / NC40) of the weight percentage of the amorphous phase in the polishing layer measured at 80°C to the weight percentage of the amorphous phase measured at 40°C is 1.50 to 2.50. Furthermore, when the content percentage is described in this specification, it is calculated on a weight basis (wt%).

[0100] In this specification, the weight percentage of the amorphous phase measured at 40°C is sometimes referred to as NC40, and the weight percentage of the amorphous phase measured at 80°C is sometimes referred to as NC80. Additionally, although described later, the weight percentage of the crystalline phase measured at 40°C is sometimes referred to as CC40, and the weight percentage of the crystalline phase measured at 80°C is sometimes referred to as CC80.

[0101] During grinding, the temperature of the grinding pad typically rises due to friction. If the pad is at a high temperature, scratches are more likely to occur, potentially reducing its performance. Specifically, if the NC80 / NC40 ratio is less than 1.50, scratches are more likely to occur, and performance may decrease. On the other hand, if the NC80 / NC40 ratio exceeds 2.50, the proportion of soft segments increases with rising temperature, causing the grinding pad to soften and the grinding rate to deteriorate, which is undesirable.

[0102] The lower limit of NC80 / NC40 is preferably 1.60 or higher, more preferably 1.70 or higher. On the other hand, the upper limit is preferably 2.40 or lower, more preferably 2.30 or lower.

[0103] Furthermore, the polishing layer is preferably calculated using the following formula (1) and has a value of 1.20 to 1.50.

[0104] [Formula 3]

[0105]

[0106] Equation (1) means that the proportion of amorphous phase increased by changing the temperature from 40°C to 80°C is greater than the proportion of crystalline phase increased by changing the temperature from 40°C to 80°C, and the value of the proportion is between 1.20 and 1.50. If the value is less than 1.20, the balance between the proportion of amorphous phase and the proportion of crystalline phase deteriorates as the temperature rises, which may adversely affect the performance of defects, especially scratches. If the value exceeds 1.50, the proportion of amorphous phase increases as the temperature rises, the polishing layer softens, and the polishing rate sometimes deteriorates. The lower limit of Equation (1) is more preferably 1.22 or more, and even more preferably 1.25 or more. In addition, the upper limit is more preferably 1.48 or less, and even more preferably 1.45 or less.

[0107] Furthermore, the NC40 of the abrasive layer is preferably 10% to 20% by weight. If the NC40 is 10% to 20% by weight, an excellent abrasive rate can be obtained, and therefore it is preferred.

[0108] Furthermore, the NC80 of the polishing layer is preferably 25% to 35% by weight. If the NC80 is 25% to 35% by weight, it has a certain amount of amorphous phase with soft chain segments when the temperature rises, thus exhibiting excellent defect performance while obtaining excellent polishing rate.

[0109] In one embodiment of the present invention, the value obtained by formula (2) in the abrasive layer of the abrasive pad is preferably 0.70 to 1.30, wherein formula (2) uses the weight ratio of the amorphous phase measured at 40°C (NC40), the weight ratio of the amorphous phase measured at 80°C (NC80), the weight ratio of the crystalline phase measured at 40°C (CC40), and the weight ratio of the crystalline phase measured at 80°C (CC80).

[0110] [Formula 4]

[0111]

[0112] Equation (2) means to calculate the ratio of amorphous phase to crystalline phase at 40℃ and 80℃ respectively. The ratio at 80℃ is greater than the ratio at 40℃, and its magnitude satisfies 0.70~1.30.

[0113] Grinding is carried out at around 40°C, but as grinding progresses, the temperature of the grinding pad may rise to around 80°C due to friction.

[0114] When the value of Equation (2) is less than 0.7 and greater than 1.30, the balance between the amorphous phase and the crystalline phase deteriorates with temperature change, thus the step elimination performance and wear resistance deteriorate.

[0115] The lower limit of the value obtained from equation (2) is preferably 0.80 or more, more preferably 0.90 or more. The upper limit of the value obtained from equation (2) is preferably 1.29 or less, more preferably 1.28 or less.

[0116] The NC40 of the abrasive layer is preferably 10% to 20% by weight. If the NC40 is 10% to 20% by weight, the abrasive pad has a suitable hardness and the step difference elimination performance becomes good, so it is preferred.

[0117] Furthermore, the NC80 of the polishing layer is preferably 25% to 35% by weight. If the NC80 is 25% or more and 35% or less by weight, it has a certain amount of amorphous phase with soft chain segments, thus exhibiting excellent step elimination performance and wear resistance.

[0118] Furthermore, the proportions of crystalline, mesophase, and amorphous phases in the polished layer were determined using pulsed NMR. In pulsed NMR measurements, the expanded polyurethane foam was classified into three phases: a short phase (S phase) with a spin-spin relaxation time less than 0.03 ms, a medium phase (M phase) with a spin-spin relaxation time greater than 0.03 ms but less than 0.2 ms, and a long phase (L phase) with a spin-spin relaxation time greater than 0.2 ms. The weight percentage of each phase was then calculated. Regarding the weight percentages of the S, M, and L phases, for example, when the crystalline phase was predominant, it was observed as the S phase in pulsed NMR measurements; when the amorphous phase was predominant, it was observed as the L phase; and when the mesophase was predominant, it was observed as the M phase. Additionally, when the hard segments were predominant, it was observed as the S phase in pulsed NMR measurements, and when the soft segments were predominant, it was observed as the L phase.

[0119] Furthermore, the spin-spin relaxation time can be determined, for example, by measurement using the solid-echo method performed by the "JNM-MU25" manufactured by JEOL.

[0120] <tanδ>

[0121] In the polishing layer of the present invention, when the polishing layer as a whole is subjected to a dynamic viscoelastic test based on a frequency of 10 rad / sec and a temperature of 20°C to 100°C in tensile mode, the maximum value of the ratio of the stored elastic coefficient E' to the lost elastic coefficient E', i.e., tanδ, is found to be within the range of 40°C to 80°C. max ) and minimum value (tanδ) min The difference is preferably less than 0.030.

[0122] tanδ is the ratio of E” (loss elasticity coefficient) to E’ (storage elasticity coefficient) (E” / E’). When the temperature of the polishing layer increases due to heat energy such as polishing heat, the proportion of amorphous phase in the polishing layer increases, and it is expected that E” (loss elasticity coefficient) will increase relative to E’ (storage elasticity coefficient). In this case, the value of tanδ is expected to increase.

[0123] However, the tanδ of the abrasive layer used in the abrasive pad of the present invention tends to decrease slightly as the temperature rises from 40°C to 80°C (for example, see reference). Figure 9 Moreover, its reduction rate is very small, with the maximum value of tanδ (tanδ) in the range of 40℃ to 80℃. max ) and minimum value (tanδ) min The difference is less than 0.030. If the maximum value (tanδ) is within the entire range of 40℃ to 80℃,... max ) and minimum value (tanδ)min If the difference is less than 0.030, then even at a grinding temperature of 80°C, there is a tendency to maintain excellent step difference elimination performance.

[0124] tanδ is determined in tensile mode using dynamic viscoelasticity testing (Dynamic Mechanical Analysis, DMA). DMA is a method that determines the mechanical properties of a specimen by applying a strain or stress that varies with time (vibration) and measuring the resulting stress or strain. By performing the measurement in tensile mode, the transverse motion of the workpiece is evaluated, thereby approximating step-reduction performance.

[0125] <Buffer Layer>

[0126] (structure)

[0127] The abrasive pad 3 of the present invention has a buffer layer 6. The buffer layer 6 ideally provides more uniform contact between the abrasive layer 4 and the workpiece 8. Examples of materials for the buffer layer 6 include: resin; impregnation materials in which the resin is impregnated in a substrate; flexible materials such as synthetic resins or rubber; and sponge materials using the resin. Examples of resins include: polyurethane, polyethylene, polybutadiene, silicone, etc., or rubbers such as natural rubber, nitrile rubber, and polyurethane rubber.

[0128] The buffer layer 6 can also be a foam with a bubble structure. As a bubble structure, in addition to a structure in which voids are formed inside the nonwoven fabric, a suede-like structure with tear-shaped bubbles formed by wet film formation or a sponge-like structure with microbubbles can preferably be used.

[0129] Among these, if a material made by impregnating polyurethane in non-woven fabric or a sponge-like material is used as a buffer layer, it has good compatibility with the abrasive layer, thus achieving a high abrasive rate while maintaining the step elimination performance.

[0130] <Next layer>

[0131] The adhesive layer 7 is used to bond the buffer layer 6 to the abrasive layer 4, and typically comprises double-sided tape or adhesive. The double-sided tape or adhesive may be a substance known in the art (e.g., adhesive sheet).

[0132] The abrasive layer 4 and the buffer layer 6 are bonded together by the adhesive layer 7. The adhesive layer 7 may be formed, for example, by at least one adhesive selected from acrylic, epoxy, and urethane adhesives. For example, an acrylic adhesive may be used, and the thickness may be set to 0.1 mm.

[0133] The abrasive pad of the present invention maintains excellent defect performance while maintaining step elimination performance, and also has excellent abrasion rate or wear resistance.

[0134] Here, the term "step elimination performance" refers to the performance measured by the time it takes for the step difference (unevenness) of a patterned wafer, which has developed step differences (unevenness) during polishing, to disappear. A schematic diagram of the experiment for measuring step elimination performance is shown below. Figure 3 The diagram illustrates, for example, the step reduction status when there is a step of 3500 angstroms in the workpiece being ground, using a grinding pad with high step reduction performance (dashed line), and a grinding pad with relatively low step reduction performance (solid line). Figure 3 At time point (a), although there was no difference, as the grinding progressed to a grinding depth of 2000 angstroms, the grinding pad with good step elimination performance (dashed line) showed a shorter time until the step disappeared compared to the grinding pad with relatively low step elimination performance (solid line) ((b)). The grinding pad with high step elimination performance eliminated the step relatively earlier ((c)). It can be said that the grinding pad shown by the dashed line has relatively higher step elimination performance compared to the grinding pad shown by the solid line.

[0135] In addition, the term "defect" refers to a general term for defects including "particles" which are substances formed by the residue of fine particles adhering to the surface of the object being polished, "pad debris" which are the debris of the polishing layer adhering to the surface of the object being polished, and "scratch" which are the damage to the surface of the object being polished. The term "defect performance" refers to the performance of reducing the aforementioned "defects".

[0136] In addition, the so-called grinding rate refers to the amount of surface material removed from the wafer per unit time through grinding. The higher the value, the better the characteristics.

[0137] In addition, wear resistance refers to the resistance of the abrasive layer (abrasive pad) to wear.

[0138] <<Manufacturing Method of Grinding Pads>>

[0139] The manufacturing method of the abrasive pad 3 of the present invention will be described.

[0140] <Materials of the Abrasive Layer>

[0141] Polyurethane resin foam is used as the material for the abrasive layer 4. Examples of materials that can be used as the main component include those obtained by reacting isocyanate-terminated prepolymers with a curing agent. Furthermore, a foaming agent is added to the material to induce foaming.

[0142] The following describes the manufacturing method of the polishing layer 4 using an example of an isocyanate-terminated prepolymer and a hardener.

[0143] As a method for manufacturing the polishing layer 4 using isocyanate-terminated prepolymer and hardener, for example, the manufacturing method includes: a material preparation step, which prepares at least an isocyanate-terminated prepolymer, an additive, and a hardener; a mixing step, which mixes at least the isocyanate-terminated prepolymer, the additive, and the hardener to obtain a molding mixture; and a molding step, which shapes the polishing layer 4 from the molding mixture.

[0144] The following sections will explain the material preparation process, the mixing process, and the forming process separately.

[0145] <Material Preparation Process>

[0146] To manufacture the abrasive layer 4 of the present invention, isocyanate-terminated prepolymers and a hardener are prepared as raw materials for the polyurethane resin foam. Here, the isocyanate-terminated prepolymer is a urethane prepolymer used to form the polyurethane resin foam.

[0147] The following is a description of each component.

[0148] (Isocyanate-terminated prepolymer)

[0149] The isocyanate-terminated prepolymer is a compound obtained by reacting a polyisocyanate compound with a polyol compound under normally used conditions. It is a compound containing urethane bonds and isocyanate groups within its molecule. Additionally, other components may be included in the isocyanate-terminated prepolymer without impairing the effects of the invention.

[0150] As isocyanate-terminated prepolymers, commercially available substances can be used, as well as compounds synthesized by reacting polyisocyanate compounds with polyol compounds. The reaction is not particularly limited, as long as an addition polymerization reaction is carried out using methods and conditions known in the manufacture of polyurethane resins. For example, it can be manufactured by adding a polyisocyanate compound heated to 50°C to a polyol compound heated to 40°C under nitrogen atmosphere with stirring, followed by raising the temperature to 80°C after 30 minutes and reacting at 80°C for 60 minutes.

[0151] Furthermore, the isocyanate-terminated prepolymer preferably has an NCO equivalent of about 300 to 600. Therefore, when the isocyanate-terminated prepolymer is a commercially available product, it is preferable that the NCO equivalent meets the aforementioned range. When manufactured by synthesis, it is preferable that the NCO equivalent is set to the aforementioned range by using the following raw materials in appropriate proportions.

[0152] (Polyisocyanate compounds)

[0153] In this specification, the term "polyisocyanate compound" refers to a compound having two or more isocyanate groups within its molecule.

[0154] As polyisocyanate compounds, there are no particular restrictions as long as they have two or more isocyanate groups within the molecule. Examples of diisocyanate compounds with two isocyanate groups within the molecule include: isophenylene diisocyanate, terephthalene diisocyanate, 2,6-tolylene diisocyanate (2,6-TDI), 2,4-tolylene diisocyanate (2,4-TDI), naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), 4,4'-methylene-bis(cyclohexyl) isocyanate (hydrogenated MDI), 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3 Polyisocyanates include '-dimethyldiphenylmethane-4,4'-diisocyanate, xylene-1,4-diisocyanate, 4,4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, terephthalene diisothiocyanate, xylene-1,4-diisothiocyanate, and ethylene diisothiocyanate. These polyisocyanate compounds can be used alone or in combination.

[0155] Furthermore, the polyisocyanate compound preferably contains 2,4-TDI and / or 2,6-TDI.

[0156] (Polyol compounds used as raw materials for isocyanate-terminated prepolymers)

[0157] In this specification, the term "polyol compound" refers to a compound having two or more hydroxyl groups (OH) within its molecule.

[0158] Examples of polyol compounds used in the synthesis of polyisocyanate compounds containing urethane bonds as isocyanate-terminated prepolymers include: ethylene glycol, diethylene glycol (hereinafter also referred to as DEG), butanediol, and other diols and triols; poly(oxytetramethylene) glycol (or polytetramethylene ether glycol) (hereinafter also referred to as PTMG), polypropylene glycol (hereinafter also referred to as PPG), and polyether polycarbonate diol (hereinafter also referred to as PEPCD), etc. Furthermore, in this specification, polyether polycarbonate diol comprises two or more ether-based polyol moieties and two or more carbonate groups.

[0159] The number of carbon atoms in the ether polyol portion of polyether polycarbonate diol is not particularly limited; for example, carbon atoms ranging from 2 to 8 can be listed. It can be a straight chain or a branched chain.

[0160] PEPCD is a compound represented by the following general formula.

[0161] [Chemistry 1]

[0162]

[0163] In the formula, m and n represent the number of repetitions of the unit, and each represents a real number independently. PEPCD can be used in one form or in combination with two or more forms.

[0164] Commercially available polyether polycarbonate diols include PEPCDNT1002, PEPCDNT2002, and PEPCDNT2006 (all manufactured by Mitsubishi Chemical Corporation).

[0165] There is no particular limitation on the number average molecular weight of polyether polycarbonate diol, but from the viewpoint of exhibiting the rubber elasticity required for abrasive pads as a soft segment, a number average molecular weight of 600 to 2500 is preferred.

[0166] From the viewpoint that it is easy to adjust NC80 / NC40 to 1.5 to 2.5 and the value of formula (1) to 1.20 to 1.50, and further from the viewpoint that it is easy to adjust the value of formula (2) to 0.70 to 1.30, PPG and PEPCD are preferred, and a combination of PPG and PEPCD is preferred.

[0167] In the case of a combination of PPG and PEPCD, the amount of polypropylene glycol used is less than 80% by weight relative to the total high molecular weight polyol. If it exceeds 80% by weight, the abrasion resistance will deteriorate. Preferably, the amount of polypropylene glycol is 30% to 70% by weight relative to the total high molecular weight polyol.

[0168] Furthermore, the polyether polycarbonate diol content is less than 80% by weight relative to the total high molecular weight polyol. If it exceeds 80% by weight, the grinding rate will decrease. Preferably, the polyether polycarbonate diol content is 30% to 70% by weight relative to the total high molecular weight polyol.

[0169] The combined amount of polypropylene glycol and polyether polycarbonate diol is preferably 80% by weight or more, relative to the total amount of high molecular weight polyol. This is because a concentration of 80% by weight or more significantly enhances the effect.

[0170] In this invention, although other high molecular weight polyols besides polypropylene glycol and polyether polycarbonate diol may be used as needed, they are used within the scope that does not impair the effects of this invention. For example, relative to the total high molecular weight polyol, polyoxytetramethylene glycol is preferably 10% by weight or less, more preferably 5% by weight or less, and even more preferably 3% by weight or less. If it is included in more than 10% by weight, the step difference elimination performance or defect performance may sometimes become insufficient.

[0171] The number average molecular weight (Mn) of the polyols such as PPG or PEPCD is not particularly limited, but is preferably 500 or more, more preferably 500 to 3000, and even more preferably 800 to 2500. It may also have a number average molecular weight (Mn) of, for example, 500 to 2000 or 650 to 1000.

[0172] Here, the number average molecular weight can be determined by gel permeation chromatography (GPC). Alternatively, when determining the number average molecular weight of polyol compounds based on polyurethane resins, it can also be inferred by GPC after decomposing the components using conventional methods such as amine decomposition.

[0173] (additive)

[0174] As described above, additives such as oxidants can be added as needed to the material of the polishing layer 4.

[0175] (hardener)

[0176] In the manufacturing method of the polishing layer 4 of the present invention, a hardener (also called a chain elongating agent) is mixed with an isocyanate-terminated prepolymer in a mixing step. By adding the hardener, in a subsequent molding step, the main chain ends of the isocyanate-terminated prepolymer bond with the hardener to form a polymer chain, thereby hardening the material.

[0177] Examples of hardening agents include: ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), 4-methyl-2,6-bis(methylthio)-1,3-phenylenediamine, 2-methyl-4,6-bis(methylthio)-1,3-phenylenediamine, and 2,2-bis(3-amino-4-hydroxyphenyl)propane. 2,2-bis[3-(isopropylamino)-4-hydroxyphenyl]propane, 2,2-bis[3-(1-methylpropylamino)-4-hydroxyphenyl]propane, 2,2-bis[3-(1-methylpentylamino)-4-hydroxyphenyl]propane, 2,2-bis(3,5-diamino-4-hydroxyphenyl)propane, 2,6-diamino-4-methylphenol, trimethyl ethylidene bis-4-aminobenzoate, and polytetramethylene Polyamine compounds such as di-p-aminobenzoate; ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 3-methyl-1,2-butanediol, 1,2-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyltrimethylenediol, and tetramethylenediol. Polyols such as 3-methyl-4,3-pentanediol, 3-methyl-4,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, 1,4-cyclohexanediol, neopentanediol, glycerol, trimethylolpropane, trimethylolethane, trimethylolmethane, poly(oxytetramethylene) glycol, polyethylene glycol, and polypropylene glycol are included. Additionally, polyamine compounds may possess hydroxyl groups. Examples of such amine compounds include 2-hydroxyethylethylenediamine, 2-hydroxyethylpropanediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropanediamine, 2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine. As a polyamine compound, a diamine compound is preferred, and more preferably, 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylene bis-o-chloroaniline) (hereinafter referred to as MOCA) is used.

[0178] Furthermore, as a raw material for the prepolymer, when using two or more polyols, a raw material obtained by mixing two or more polyols and reacting the polyisocyanate compound with the mixture can be used, or a method can be used to react two or more polyols separately with the polyisocyanate compound, mix them, and then harden them.

[0179] The abrasive layer 4 can be formed by using hollow microspheres 4A with a shell and a hollow interior in the material. Commercially available materials or materials synthesized using conventional methods can be used as the material for the hollow microspheres 4A. There are no particular limitations on the material of the shell of the hollow microspheres 4A; examples include: polyvinyl alcohol, polyvinylpyrrolidone, poly(meth)acrylic acid, polyacrylamide, polyethylene glycol, polyhydroxy ether acrylate, maleic acid copolymer, polyethylene oxide, polyurethane, poly(meth)acrylonitrile, polyvinylidene chloride, polyvinyl chloride, and silicone resins, as well as copolymers combining two or more monomers of these resins (e.g., acrylonitrile-vinylidene chloride copolymer, etc.). In addition, commercially available hollow microspheres are not limited to the following, for example, the Expancel Series (a trade name manufactured by Akzo Nobel) and the Matsumoto Microsphere (a trade name manufactured by Matsumoto Oils, Inc.).

[0180] The gas contained in the hollow microsphere 4A is not particularly limited; for example, hydrocarbons can be listed, specifically isobutane, pentane, isopentane, etc.

[0181] The shape of the hollow microspheres 4A is not particularly limited; for example, they can be spherical or approximately spherical. The average particle size of the hollow microspheres 4A is not particularly limited, but is preferably 5 μm to 200 μm, more preferably 5 μm to 80 μm, even more preferably 5 μm to 50 μm, and particularly preferably 5 μm to 35 μm. Furthermore, the average particle size can be measured using a laser diffraction particle size distribution measuring device (e.g., Spectris Mastersizer-2000 particle size analyzer).

[0182] The material of the hollow microspheres 4A is added in a manner that is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, and even more preferably 1 to 4 parts by mass relative to 100 parts by mass of the isocyanate-terminated prepolymer.

[0183] In addition to the aforementioned components, the previously used foaming agent may be used in combination with the hollow microspheres 4A without impairing the effects of the present invention, and a gas that is non-reactive to each of the aforementioned components may be blown in during the following mixing process. As the foaming agent, in addition to water, foaming agents with hydrocarbons having 5 or 6 carbon atoms as the main component may also be listed. Examples of such hydrocarbons include chain hydrocarbons such as n-pentane and n-hexane, or alicyclic hydrocarbons such as cyclopentane and cyclohexane.

[0184] The hollow microspheres 4A contained in the abrasive layer 4 of the abrasive pad of the present invention can be identified as hollow bodies in the abrasive surface or cross-section of the abrasive layer 4. The hollow bodies typically have an opening diameter (diameter of the hollow microsphere 4A) of 2 μm to 200 μm. The shapes of the hollow microspheres 4A can be spherical, elliptical, and similar shapes.

[0185] The hollow microspheres 4A can be commercially available balloons, including both inflated and uninflated balloons. Uninflated balloons are heat-expandable microspheres that can expand upon heating. In this invention, they can be used after expanding by heating, or added to a mixture in their uninflated state, expanding upon heating during a reaction or due to heat generated by the reaction heat.

[0186] <Mixed Process>

[0187] In the mixing process, the isocyanate-terminated prepolymer, additives, and hardener obtained in the preparation process are fed into a mixer for stirring and mixing. The mixing process is carried out at a temperature that ensures the flowability of each component.

[0188] <Forming Process>

[0189] In the molding process, the molding mixture prepared in the mixing process is poured into a mold frame preheated to 30°C–100°C for primary hardening, followed by secondary hardening at approximately 100°C–150°C for 10 minutes–5 hours, thereby molding the hardened polyurethane resin (polyurethane resin foam). At this point, the isocyanate-terminated prepolymer and the hardener react to form hardened polyurethane resin.

[0190] If the viscosity of the urethane prepolymer (isocyanate-terminated prepolymer) is too high, its flowability will be poor, making it difficult to mix approximately uniformly during mixing. If the temperature increases and the viscosity decreases, the pot life will be shortened, resulting in uneven mixing and deviations in the size of the hollow microspheres 4A formed in the obtained foam. Conversely, if the viscosity is too low, bubbles will move in the mixture, making it difficult to form hollow microspheres 4A that are approximately evenly dispersed in the obtained foam. Therefore, the prepolymer is preferably set to a viscosity in the range of 500 mPa·s to 10000 mPa·s at a temperature of 50°C to 80°C. This can be achieved, for example, by changing the molecular weight (degree of polymerization) of the prepolymer. The prepolymer is heated to approximately 50°C to 80°C to achieve a flowable state.

[0191] During the molding process, the poured mixture is reacted within the mold frame as needed to form a foam. At this point, the prepolymer cross-links and hardens through the reaction between the prepolymer and the hardener.

[0192] After obtaining the molded body, it is sliced ​​into sheets to form multiple polishing layers 4. A general slicing machine can be used for slicing. When slicing, the lower part of the polishing layer 4 is kept in place, and the slices are cut sequentially to a specified thickness starting from the upper part. The thickness of the slices is set, for example, in the range of 0.8 mm to 2.5 mm. In a foam body with a thickness of 50 mm formed using a mold frame, for example, about 10 mm of the upper and lower parts of the foam body are not used due to scratches, etc., and 10 to 25 polishing layers 4 are formed from the central part of about 30 mm. In the hardening molding process, a foam body with hollow microspheres 4A formed approximately evenly inside is obtained.

[0193] Grooving is performed on the grinding surface of the obtained grinding layer 4 as needed. Grooves with arbitrary spacing, width, and depth can be formed by cutting the grinding surface using a required tool. For example, circular grooves formed in a concentric circle shape can be used as slurry holding grooves, and linear grooves formed in a grid shape or linear grooves formed radially from the center of the grinding layer can be used as slurry discharge grooves.

[0194] Regarding the polishing layer 4 thus obtained, double-sided tape is then applied to the side of the polishing layer 4 opposite to the polishing surface. There are no particular limitations on the double-sided tape; any type of double-sided tape known in the art can be used.

[0195] <Manufacturing Method of Buffer Layer 6>

[0196] As described above, known materials and manufacturing methods can be used for the cushioning layer 6. Examples of materials for the cushioning layer 6 include: impregnated materials made by impregnating a resin solution such as urethane into resin fibers (non-woven fabrics, flexible films, etc.) such as polyethylene or polyester; suede-like materials using resin materials such as urethane; and sponge materials using materials such as urethane.

[0197] The buffer layer 6 is preferably an impregnated nonwoven fabric containing an impregnated resin. Preferred resins for impregnation include: polyurethane-based resins such as polyurethane and polyurethane-polyurea; acrylic-based resins such as polyacrylate and polyacrylonitrile; vinyl-based resins such as polyvinyl chloride, polyvinyl acetate and polyvinylidene fluoride; polysulfone-based resins such as polysulfone and polyethersulfone; acylated cellulose-based resins such as acetylated cellulose and butyrylated cellulose; polyamide-based resins; and polystyrene-based resins. Regarding the density of the nonwoven fabric, in its state before resin impregnation (sheet state), it is preferably 0.3 g / cm³. 3 The following is more preferably 0.1 g / cm³. 3 ~0.2g / cm 3 Furthermore, the density of the resin-impregnated nonwoven fabric is preferably 0.7 g / cm³. 3The following is more preferably 0.25 g / cm³. 3 ~0.5g / cm 3 By ensuring that the density of the nonwoven fabric before and after resin impregnation is below the upper limit, processing accuracy is improved. Furthermore, by ensuring that the density of the nonwoven fabric before and after resin impregnation is above the lower limit, the penetration of the abrasive slurry into the substrate layer can be reduced. The resin adhesion rate to the nonwoven fabric is expressed as the weight of the resin adhered to relative to the weight of the nonwoven fabric, preferably 50% by weight or more, more preferably 75% by weight to 200% by weight. By ensuring that the resin adhesion rate to the nonwoven fabric is below the upper limit, the desired cushioning properties can be achieved.

[0198] <Jointing Process>

[0199] In the bonding process, the formed abrasive layer 4 and buffer layer 6 are bonded together using adhesive layer 7. Adhesive layer 7 is formed, for example, using an acrylic adhesive, with a thickness of 0.1 mm. That is, an acrylic adhesive is applied to the side of the abrasive layer 4 opposite to the abrasive surface with a substantially uniform thickness. The side of the abrasive layer 4 opposite to the abrasive surface and the surface of the buffer layer 6 (the side with the surface layer) are pressed together using the applied adhesive, thereby bonding the abrasive layer 4 and the buffer layer 6 together using adhesive layer 7. Then, after being cut into the desired shape such as a circle, an inspection is performed to confirm the absence of dirt or foreign matter, thereby completing the abrasive pad 3.

[0200] [Example]

[0201] The present invention will now be described in more detail by way of examples, but the present invention is not limited to these examples.

[0202] In all embodiments and comparative examples, unless otherwise specified, the term "parts" refers to "parts by mass".

[0203] In addition, the so-called NCO equivalent is the molecular weight of the prepolymer (PP) with each NCO group, calculated using "(mass (parts) of polyisocyanate compound + mass (parts) of polyol compound)) / [(number of functional groups per molecule of polyisocyanate compound × mass (parts) of polyisocyanate compound / molecular weight of polyisocyanate compound) - (functional groups per molecule of polyol compound × mass (parts) of polyol compound / molecular weight of polyol compound)]".

[0204] [Examples 1-3, and Comparative Example 1]

[0205] (Regarding the polishing layer)

[0206] 2,4-Toluene diisocyanate (TDI) as an isocyanate compound, and PPG, PTMG, PEPCD, and diethylene glycol (DEG) as polyol compounds were reacted to prepare urethane prepolymer 1, urethane prepolymer 2, and urethane prepolymer 3 (the components used in the preparation of the urethane prepolymers are shown in Table 1). To 100 parts of a urethane prepolymer mixture prepared according to the proportions shown in Table 2, 2.9 parts of unexpanded hollow microspheres containing acrylonitrile-vinylidene chloride copolymer in the shell and encapsulating isobutane gas were added to obtain a mixture. The obtained mixture was placed in a first liquid tank and kept at 60°C. Next, separately from the first liquid, 27.8 parts of MOCA as a hardener were added to a second liquid tank, heated to 120°C for melting, and kept at that temperature. The liquids from the first and second liquid tanks were injected into the mixer through two injection ports, with an R value of 0.9 representing the equivalent ratio of amino and hydroxyl groups present in the hardener to the terminal isocyanate groups in the prepolymer. The two liquids were mixed and stirred while being injected into the mold of a preheated molding machine. The mold was then closed, and the mixture was heated at 80°C for 30 minutes for primary hardening. After demolding the primary hardened product, it was subjected to secondary hardening in an oven at 120°C for 4 hours to obtain a urethane molded product. After cooling the obtained urethane molded product to 25°C, it was heated again in an oven at 120°C for 5 hours and then cut into 1.3 mm thicknesses to obtain polished layers 1 to 4 as shown in Table 2. The density and D-hardness of each polished layer are shown in Table 3, and the proportions of crystalline, mesophase, and amorphous phases obtained using pulsed NMR are shown in Table 4. Furthermore, the measurement methods and conditions for density, D-hardness, and pulsed NMR are as described below.

[0207] (density)

[0208] Density of the grinding layer (g / cm³) 3 The test was conducted in accordance with Japanese Industrial Standards (JIS K 6505).

[0209] (Shore D hardness)

[0210] The Shore D hardness of the abrasive layer was measured using a Shore D type hardness tester according to Japanese Industrial Standard (JIS-K-6253). The test specimens were obtained by overlapping multiple abrasive layers as needed, with a total thickness of at least 4.5 mm.

[0211] (Pulse NMR measurement)

[0212] The device is a Bruker Minispec MQ20 ​​(20MHz).

[0213] Repeat time 4 seconds

[0214] Measurement method: Solid echo method

[0215] Total number of times: 16

[0216] Temperatures measured at 40℃ and 80℃

[0217] [Table 1]

[0218] NCO equivalent composition Remark Prepolymer 1 420 2,4-TDI / PPG / DEG PPG with an average molecular weight of 1000 Prepolymer 2 420 2,4-TDI / PTMG / DEG PTMG with an average molecular weight of 850 Prepolymer 3 420 2,4-TDI / PEPCD / DEG PEPCD with a number average molecular weight of 1000

[0219] [Table 2]

[0220] carbamate prepolymer Prepolymer composition PPG blending ratio hardener Hollow microspheres Polishing layer 1 (Comparative Example 1) Prepolymer 2 PTMG: 100% 0 MOCA Unexpanded type Polishing layer 2 (Example 1) Prepolymer 1 + Prepolymer 3 PPG:PEPCD = 7:3 70 MOCA Unexpanded type Polishing layer 3 (Example 2) Prepolymer 1 + Prepolymer 3 PPG:PEPCD = 5:5 50 MOCA Unexpanded type Polishing layer 4 (Example 3) Prepolymer 1 + Prepolymer 3 PPG:PEPCD = 3:7 30 MOCA Unexpanded type

[0221] [Table 3]

[0222] <![CDATA[Density (g / cm 3 )]]> D Hardness (degrees) Polishing layer 1 (Comparative Example 1) 0.783 62.0 Polishing layer 2 (Example 1) 0.780 63.5 Polishing layer 3 (Example 2) 0.781 63.5 Polishing layer 4 (Example 3) 0.778 63.5

[0223] [Table 4]

[0224]

[0225] (Regarding the buffer layer)

[0226] In a resin solution (dimethylformamide (DMF) solvent) containing urethane resin (manufactured by DIC, product name "C1367"), the impregnation density is 0.15 g / cm³. 3 The process involves impregnating a nonwoven fabric containing polyester fibers. After impregnation, a mangle roller is used to apply pressure between a pair of rollers, extruding the resin solution from the nonwoven fabric to ensure the resin solution is approximately uniformly impregnated. The resin-impregnated nonwoven fabric is then wet-coagulated by immersing it in a coagulation solution containing water at room temperature, resulting in a resin-impregnated nonwoven fabric. The resin-impregnated nonwoven fabric is then removed from the coagulation solution and washed with a cleaning solution containing water to remove N,N-dimethylformamide (DMF) from the resin, followed by drying. After drying, the surface layer of the resin-impregnated nonwoven fabric is removed by polishing, resulting in a 1.3 mm thick buffer layer containing the resin-impregnated nonwoven fabric.

[0227] (Examples and Comparative Examples)

[0228] Abrasive layers 1 to 4 and a buffer layer were bonded together using double-sided tape with a thickness of 0.1 mm (which includes an adhesive layer containing an acrylic resin on both sides of a polyethylene terephthalate (PET) substrate). The double-sided tape was then applied to the side of the buffer layer opposite to the adhesive layer to manufacture abrasive pads of Examples 1 to 3 and Comparative Example 1.

[0229] (Grinding performance evaluation)

[0230] Using the abrasive pads obtained in Examples 1 to 3 and Comparative Example 1, abrasive tests were conducted under the following abrasive conditions. The results are shown in Table 5.

[0231] (Grinding conditions)

[0232] Grinding machine used: F-REX300X (manufactured by Ebara Seisakusho Co., Ltd.)

[0233] Disk: A188 (manufactured by 3M)

[0234] Abrasive temperature: 20℃

[0235] Grinding platen speed: 90 rpm

[0236] Grinding head speed: 81 rpm

[0237] Grinding pressure: 3.5 psi

[0238] Grinding slurry (metallic film): CSL-9044C (using a mixture of CSL-9044C stock solution and pure water at a weight ratio of 1:9) (manufactured by Fujifilm Planar Solutions)

[0239] Grinding slurry flow rate: 200ml / min

[0240] Grinding time: 60 seconds

[0241] Materials to be polished: Cu film substrate (polishing performance evaluation test), patterned wafer described later (step elimination performance test).

[0242] Pad break-in: 32N for 10 minutes

[0243] Conditioning: In-situ 18N 16 scans, Ex-situ 32N 4 scans

[0244] The polishing rate (thickness polished within a 60-second polishing time) of the 15th, 25th, and 50th substrates was measured. Furthermore, in this embodiment, the polishing rate was evaluated using the thickness after polishing.

[0245] [Table 5]

[0246]

[0247] (Analysis of grinding test results)

[0248] The results in Table 5 show that the grinding pads of Examples 1 to 3 have a higher grinding rate and better grinding performance compared with the grinding pad of Comparative Example 1.

[0249] (Step Elimination Performance Test)

[0250] The abrasive pads of the examples and comparative examples were placed at a predetermined position in the abrasive apparatus via double-sided adhesive tape with an acrylic adhesive, and abrasive processing was performed under the stated abrasive conditions. The step elimination performance was evaluated by measuring 100 μm / 100 μm dishing using a step / surface roughness / micro-shape measuring device (KLA Tencor, P-16+). The evaluation results are shown below. Figure 4 middle.

[0251] For a patterned wafer with a film thickness of 7000 angstroms and a step difference of 3000 angstroms, the polishing rate is adjusted to 1000 angstroms per polishing pass, and polishing is performed in stages, with the step difference of the wafer measured each time. The step height on the vertical axis represents the step difference.

[0252] Figure 4 The 120μm indicates a wiring width of 120μm. Figure 5 The 100 / 100 indicates that the insulation film width is 100μm relative to the Cu wiring width of 100μm. Figure 6 The 50 / 50 indicates that the insulation film width is 50μm relative to the Cu wiring width of 50μm. Figure 7 The 10 / 10 indicates that the insulation film has a width of 10μm relative to the Cu wiring width of 10μm. The smaller the number, the finer the wiring becomes.

[0253] Depend on Figures 4-7 The results showed that the abrasive pads of Examples 1 to 3 had the same step elimination performance as the abrasive pad of Comparative Example 1.

[0254] (Defect Performance Evaluation)

[0255] For substrates numbered 27, 28, and 50 after polishing, a surface inspection device (KLA Tencor, Surfscan SP2XP) in high-sensitivity measurement mode was used to detect and count minute scratches (fine dents larger than 0.02 μm and smaller than 0.16 μm) on the substrate surface. The results are shown below. Figure 8 middle.

[0256] Depend on Figure 8 The results showed that, compared with Comparative Example 1, the number of micro-scratches in the abrasive pads of Examples 1 to 3 was slightly reduced, which could suppress the generation of defects.

[0257] [Examples 4-6, and Comparative Examples 2 and 3]

[0258] (Regarding the polishing layer)

[0259] 2,4-Toluene diisocyanate (TDI), an isocyanate compound, and PPG and PEPCD, polyol compounds, were reacted to prepare isocyanate-terminated prepolymers 4 and 5 (the components used in the preparation of the isocyanate-terminated prepolymers are shown in Table 6). To 100 parts of each isocyanate-terminated prepolymer prepared according to the proportions in Table 7, 2.7 parts of expanded hollow microspheres containing acrylonitrile-vinylidene chloride copolymer in the shell and encapsulating isobutane gas were added to obtain a mixture. The obtained mixture was placed in a first liquid tank and kept at 60°C. Next, separately from the first liquid, 23.5 parts of MOCA, a curing agent, were added to a second liquid tank, heated to 120°C for melting, and kept at that temperature. The liquids from the first and second liquid tanks were injected into the mixer through two injection ports, with an R value of 0.9 representing the equivalent ratio of amino and hydroxyl groups present in the hardener to the terminal isocyanate groups in the prepolymer. The two liquids were mixed and stirred while being injected into the mold of a preheated molding machine. The mold was then closed, and the mixture was heated at 80°C for 30 minutes for primary hardening. After demolding the primary hardened product, it was subjected to secondary hardening in an oven at 120°C for 4 hours to obtain a urethane molded product. After cooling the obtained urethane molded product to 25°C, it was heated again in an oven at 120°C for 5 hours and then cut into 1.3 mm thicknesses to obtain polished layers 5 to 9 as shown in Table 7. The density and Schottky D hardness of each polished layer are shown in Table 8, and the proportions of crystalline, mesophase, and amorphous phases are shown in Table 9. Furthermore, the pulse NMR measurement method and conditions are as described below.

[0260] (density)

[0261] Density of the grinding layer (g / cm³) 3 The test was conducted in accordance with Japanese Industrial Standard (JIS K 6505).

[0262] (Shore D hardness)

[0263] The Shore D hardness of the abrasive layer was measured using a type D hardness tester according to Japanese Industrial Standard (JIS-K-6253). The test specimens were obtained by overlapping multiple abrasive layers as needed, ensuring a total thickness of at least 4.5 mm.

[0264] (Pulse NMR measurement)

[0265] The device is a Bruker Minispec MQ20 ​​(20MHz).

[0266] Repeat time 4 seconds

[0267] Measurement method: Solid echo method

[0268] Total number of times: 16

[0269] Temperatures measured at 40℃ and 80℃

[0270] [Table 6]

[0271] NCO equivalent composition Remark Prepolymer 4 500 2,4-TDI / PPG / DEG PPG with an average molecular weight of 1200 Prepolymer 5 500 2,4-TDI / PEPCD / DEG PEPCD with a number average molecular weight of 1000

[0272] [Table 7]

[0273] carbamate prepolymer Prepolymer composition PPG blending ratio hardener Hollow microspheres Polishing layer 5 (Comparative Example 2) Prepolymer 4 PPG: 100% 100 MOCA Expansion type Polishing layer 6 (Example 4) Prepolymer 4 + Prepolymer 5 PPG:PEPCD = 7:3 70 MOCA Expansion type Polishing layer 7 (Example 5) Prepolymer 4 + Prepolymer 5 PPG:PEPCD = 5:5 50 MOCA Expansion type Polishing layer 8 (Example 6) Prepolymer 4 + Prepolymer 5 PPG:PEPCD = 3:7 30 MOCA Expansion type Polishing layer 9 (Comparative Example 3) Prepolymer 5 PEPCD: 100% 0 MOCA Expansion type

[0274] [Table 8]

[0275] <![CDATA[Density (g / cm 3 )]]> D Hardness (degrees) Polishing layer 5 (Comparative Example 2) 0.786 52.0 Polishing layer 6 (Example 4) 0.820 54.5 Polishing layer 7 (Example 5) 0.815 53.5 Polishing layer 8 (Example 6) 0.833 53.0 Polishing layer 9 (Comparative Example 3) 0.813 52.5

[0276] [Table 9]

[0277]

[0278] (Dynamic viscoelasticity measurement (tanδ))

[0279] Polishing layers 5 to 9 were used as samples for DMA (Dynamic Viscoelasticity Measurement). The samples were dried after being kept in a constant temperature and humidity bath at a set temperature of 23℃ (21℃ to 25℃) and a set relative humidity of 50% (45% to 55%) for 40 hours.

[0280] Measurements were performed under normal atmospheric conditions (dry state) using a tensile mode. Other conditions are as follows. The ratio (E” / E’) of the obtained E” (loss elasticity coefficient) and E’ (storage elasticity coefficient) was calculated, and tanδ was obtained. The results of Example 6 are shown below. Figure 9 In the comparison, the results of Example 2 are shown in Figure 10 The maximum, minimum, and difference values ​​of each data point are summarized in Table 10.

[0281] Device: RSA-G2 (TA Instruments)

[0282] Sample dimensions: 5cm (length) × 0.5cm (width) × 0.125cm (thickness)

[0283] Test mode: Tensile mode

[0284] Frequency: 10 rad / sec (1.6 Hz)

[0285] Measurement temperature: 20℃~100℃

[0286] Strain range: 0.10%

[0287] Test length: 1cm

[0288] Heating rate: 5.0℃ / min

[0289] Initial load: 148g

[0290] Measurement interval: 2 points / ℃

[0291] [Table 10]

[0292]

[0293] (Regarding the buffer layer)

[0294] In a resin solution (DMF solvent) containing urethane resin (manufactured by DIC, product name "C1367"), the impregnation density is 0.15 g / cm³. 3 The process involves impregnating a nonwoven fabric containing polyester fibers. After impregnation, a resin solution is extruded from the nonwoven fabric using a pressure roller capable of applying pressure between a pair of rollers, resulting in a substantially uniform impregnation of the nonwoven fabric with the resin solution. Subsequently, the resin-impregnated nonwoven fabric is wet-coagulated by immersing it in a coagulation solution containing water at room temperature, thus obtaining a resin-impregnated nonwoven fabric. The resin-impregnated nonwoven fabric is then removed from the coagulation solution and washed with a cleaning solution containing water to remove N,N-dimethylformamide (DMF) from the resin, followed by drying. After drying, the surface layer of the resin-impregnated nonwoven fabric is removed by polishing, resulting in a 1.3 mm thick buffer layer containing the resin-impregnated nonwoven fabric.

[0295] (Examples and Comparative Examples)

[0296] The abrasive layers 5 to 9 and the buffer layer were bonded together using double-sided tape with a thickness of 0.1 mm (which includes an adhesive layer containing acrylic resin on both sides of the PET substrate). The double-sided tape was then applied to the side of the buffer layer opposite to the adhesive layer to manufacture the abrasive pads of Examples 4 to 6 and Comparative Examples 2 and 3.

[0297] (Abrasion test)

[0298] The obtained abrasive pads were subjected to abrasion tests using a small tribological testing machine under the following conditions. After the abrasion tests, the thickness of the abrasive layer (abrasion loss) was measured. The results are shown in Table 11.

[0299] (Abrasion test conditions)

[0300] Using a grinding machine: Small friction and wear testing machine

[0301] Indenter side: PAD (17φ)

[0302] Pressure plate side: #180 sandpaper

[0303] Load capacity: 300g

[0304] Liquid: Water

[0305] Flow rate: 45ml / minute

[0306] Press plate speed: 40 rpm

[0307] Time: 10 minutes

[0308] Thickness measurement load: 300g

[0309] [Table 11]

[0310] Wear amount (mm) Comparative Example 2 0.21 Example 4 0.13 Example 5 0.12 Example 6 0.10 Comparative Example 3 0.10

[0311] Increasing the PPG blending ratio in the prepolymer leads to increased abrasion and deterioration of abrasion resistance. It has been found that the increase in abrasion is suppressed when the PPG blending ratio is low.

[0312] (Step Elimination Performance Test)

[0313] The abrasive pads of the examples and comparative examples were placed at specified positions on the abrasive apparatus using double-sided adhesive tape with an acrylic adhesive, and abrasive processing was performed under the following abrasive conditions. The step elimination performance was evaluated by measuring 100 μm / 100 μm depressions using a step / surface roughness / micro-shape measuring device (KLA Tencor, P-16+). The evaluation results are shown below. Figure 11 middle.

[0314] For a patterned wafer with a film thickness of 7000 angstroms and a step difference of 3000 angstroms, the polishing rate is adjusted to 1000 angstroms per polishing pass, and polishing is performed in stages, with the step difference of the wafer measured each time. The step height on the vertical axis represents the step difference.

[0315] Figure 11 The 100 / 100 indicates that the insulation film width is 100μm relative to the Cu wiring width of 100μm. Figure 12 The 50 / 50 indicates that the insulation film width is 50μm relative to the Cu wiring width of 50μm. The smaller the number, the finer the wiring becomes.

[0316] (Grinding conditions)

[0317] Grinding machine used: F-REX300X (manufactured by Ebara Seisakusho Co., Ltd.)

[0318] Disk: A188 (manufactured by 3M)

[0319] Abrasive temperature: 20℃

[0320] Grinding platen speed: 90 rpm

[0321] Grinding head speed: 81 rpm

[0322] Grinding pressure: 3.5 psi

[0323] Grinding slurry: CSL-9044C (using a mixture of CSL-9044C stock solution and pure water at a weight ratio of 1:9) (manufactured by Fujifilm Planar Solutions)

[0324] Grinding slurry flow rate: 200ml / min

[0325] Grinding time: 60 seconds

[0326] The object being ground: the patterned wafer

[0327] Pad break-in: 32N for 10 minutes

[0328] Adjustment: In-situ 18N 16 scans, Ex-situ 32N 4 scans

[0329] Depend on Figure 11 The results showed that the abrasive pads of Examples 4 to 6 were equivalent to the abrasive pad of Comparative Example 2, and had superior step elimination performance compared with the abrasive pad of Comparative Example 3.

[0330] [Examples 7-9 and Comparative Examples 4 and 5]

[0331] (Manufacturing of the polishing layer)

[0332] To 100 parts of an isocyanate-terminated urethane prepolymer with an NCO equivalent of 420, obtained by reacting 2,4-toluene diisocyanate (TDI) and the high molecular weight polyols shown in Table 12, 3 parts of unexpanded hollow microspheres containing acrylonitrile-vinylidene chloride copolymer in the shell and isobutane gas encapsulated within the shell were added to obtain a mixture. The obtained mixture was placed in a first liquid tank and kept at a temperature. Next, 28.6 parts of MOCA as a curing agent were separately placed in a second liquid tank, and kept at a temperature in the second liquid tank, independent of the first liquid tank. The liquids from the first and second liquid tanks were injected into the mixer through the respective injection ports of a mixer including two injection ports, such that the R value, which represents the equivalent ratio of amino and hydroxyl groups present in the curing agent to the terminal isocyanate groups in the prepolymer, was 0.90. The two liquids were mixed and stirred while being poured into a mold in a molding machine preheated to 80°C. The mold was then closed and heated for 30 minutes for initial hardening. After demolding, the hardened material was subjected to a second hardening process at 120°C for 4 hours in an oven to obtain a urethane molded product. After cooling to 25°C, the urethane molded product was heated again at 120°C for 5 hours in an oven and then cut into 1.3mm thicknesses to obtain the various polished layers.

[0333] (Manufacturing of the buffer layer)

[0334] A nonwoven fabric containing polyester fibers is impregnated in a urethane resin solution (manufactured by DIC, trade name "C1367"). After impregnation, the resin solution is extruded using a pressure roller capable of applying pressure between a pair of rollers, so that the resin solution is impregnated into the nonwoven fabric in a substantially uniform manner. Subsequently, the impregnated resin is coagulated and regenerated by impregnation in a coagulation solution containing water at room temperature, resulting in a resin-impregnated nonwoven fabric. The resin-impregnated nonwoven fabric is then removed from the coagulation solution and impregnated in a cleaning solution containing water to remove N,N-dimethylformamide (DMF) from the resin, followed by drying. After drying, the surface layer is removed by a buffing process to create a 1.3 mm thick buffer layer.

[0335] (Examples and Comparative Examples)

[0336] The abrasive layers and buffer layers formed from the components shown in Table 12 were bonded together using double-sided adhesive tape with a thickness of 0.1 mm (containing an adhesive containing acrylic resin on both sides of the PET substrate) to manufacture the abrasive pads of Examples 7 to 9 and Comparative Example 4. The previously known abrasive pad IC1000 (manufactured by Nitta Haas) was used as Comparative Example 5.

[0337] Additionally, PEPCD represents polyether polycarbonate diol with a number average molecular weight of 1000, PPG represents polypropylene glycol with a number average molecular weight of 1000, and PTMG represents polyoxytetramethylene glycol with a number average molecular weight of 850.

[0338] As a comparative example 4, an abrasive pad using only PTMG as a high molecular weight polyol was manufactured, exhibiting the same density and hardness as in Examples 7 to 9.

[0339] [Table 12]

[0340]

[0341] (density)

[0342] Density of the grinding layer (g / cm³) 3 The test was conducted in accordance with Japanese Industrial Standard (JIS K 6505).

[0343] (D hardness)

[0344] The D-hardness of the abrasive layer was measured using a type D hardness tester according to Japanese Industrial Standard (JIS-K-6253). The test specimens were obtained by overlapping multiple abrasive layers as needed, ensuring a total thickness of at least 4.5 mm.

[0345] (Abrasion test)

[0346] For the obtained abrasive pads, abrasion tests were conducted using a small tribological testing machine under the following conditions. A graph showing the abrasion amount (thickness) on the vertical axis and the PPG mixing ratio on the horizontal axis is plotted below. Figure 13 middle.

[0347] (Abrasion test conditions)

[0348] Using a grinding machine: Small friction and wear testing machine

[0349] Indenter side: PAD (17φ)

[0350] Pressure plate side: #180 sandpaper

[0351] Load capacity: 300g

[0352] Liquid: Water

[0353] Flow rate: 45ml / minute

[0354] Press plate speed: 40 rpm

[0355] Time: 10 minutes

[0356] Thickness measurement load: 300g

[0357] As by Figure 13 It was found that increasing the PPG blending ratio in high molecular weight polyols would increase abrasion loss and worsen abrasion resistance. When the PPG blending ratio is low, the increase in abrasion loss is suppressed; however, if the PPG blending ratio exceeds a specified value, the abrasion loss increases dramatically.

[0358] In addition, the grinding rate was set to 100% of the PEPCD mixing ratio, which was the same as that of Comparative Examples 4 and 5.

[0359] (Grinding performance evaluation)

[0360] Using the abrasive pads obtained in Examples 7 to 9 and Comparative Examples 4 and 5, a polishing test was conducted under the following polishing conditions.

[0361] (Grinding conditions)

[0362] Grinding machine used: F-REX300X (manufactured by Ebara Seisakusho Co., Ltd.)

[0363] Disk: A188 (manufactured by 3M)

[0364] Abrasive temperature: 20℃

[0365] Grinding platen speed: 85 rpm

[0366] Grinding head speed: 86 rpm

[0367] Grinding pressure: 3.5 psi

[0368] Grinding slurry (metal film): CSL-9044C (using a mixture of CSL-9044C stock solution and pure water at a weight ratio of 1:9) (manufactured by Fujimi Corporation)

[0369] Grinding slurry flow rate: 200ml / min

[0370] Grinding time: 60 seconds

[0371] The object being polished (metal film): Cu film substrate

[0372] Pad break-in: 35N for 10 minutes

[0373] Adjustment: Ex-situ, 35N, 4 scans

[0374] (Grinding rate)

[0375] The polishing pad is positioned at a predetermined location on the polishing apparatus using double-sided adhesive tape with an acrylic adhesive, and polishing is performed under the specified polishing conditions. Then, the polishing rate (in angstroms) of the 15th, 25th, and 50th substrates is measured. The results are presented below. Figure 14 middle.

[0376] (Defect Performance Evaluation)

[0377] For substrates at the 15th, 25th, and 50th polished wafers, defects larger than 90 nm were detected using the high-sensitivity measurement mode of a surface inspection device (KLA Tencor, Surfscan SP2XP). For each detected defect, SEM images taken using a review scanning electron microscope (review SEM) were analyzed to measure the number of scratches. The results are presented below. Figure 15 middle.

[0378] As by Figure 14 As such, the abrasive pads of Examples 7 to 9 showed a grinding rate that was about 5% to 10% higher than that of Comparative Example 4, which contained only PTMG as a high molecular weight polyol and exhibited the same density and hardness, or the abrasive pad of the previously known Comparative Example 5.

[0379] In addition, as by Figure 15 As it was found, the abrasive pads of Examples 7 to 9 showed a significant reduction in scratches compared to the previously known abrasive pad of Comparative Example 5, and a slight reduction in scratches compared to Comparative Example 4, demonstrating excellent defect performance.

[0380] [Industry availability]

[0381] This invention facilitates the manufacture and sale of abrasive pads, and therefore has industrial applicability.

Claims

1. An abrasive pad having an abrasive layer comprising a polyurethane resin foam, said polyurethane resin foam being derived from an isocyanate-terminated prepolymer and a hardener, wherein the abrasive pad, The weight ratio of the amorphous phase in the polished layer, NC80, as determined by pulsed nuclear magnetic resonance at 80°C, to the weight ratio of the amorphous phase in the polished layer, NC40, as determined by pulsed nuclear magnetic resonance at 40°C, is 1.5 to 2.

5.

2. The polishing pad according to claim 1, wherein the value obtained by Formula 1 is 1.20 to 1.50, wherein Formula 1 uses the weight ratio of the amorphous phase and the crystalline phase in the polishing layer determined by pulsed nuclear magnetic resonance at 40°C and 80°C. .

3. The abrasive pad according to claim 1 or 2, wherein the NC40 is 10% to 20% by weight.

4. The abrasive pad according to claim 1 or 2, wherein the NC80 is 25% to 35% by weight.

5. The abrasive pad according to claim 1 or 2, wherein the abrasive layer comprises polypropylene glycol and polyether polycarbonate diol.

6. The abrasive pad according to claim 5, wherein the ratio of the polyether polycarbonate diol to the total of the polypropylene glycol and the polyether polycarbonate diol is less than 80%.

7. An abrasive pad having an abrasive layer comprising a polyurethane resin foam, said polyurethane resin foam being derived from an isocyanate-terminated prepolymer and a hardener, wherein in the abrasive pad, The value obtained from Equation 2 is 0.70 to 1.30, where Equation 2 uses the weight ratio of amorphous and crystalline phases in the polished layer, determined by pulsed nuclear magnetic resonance at 40°C and 80°C. 。 8. The abrasive pad according to claim 7, wherein the difference between the maximum and minimum values ​​of tanδ obtained by measuring the abrasive layer using a dynamic viscoelasticity test at 40°C to 80°C is less than 0.

030.

9. The abrasive pad according to claim 7 or 8, wherein the NC40 is 10% to 20% by weight.

10. The abrasive pad according to claim 7 or 8, wherein the NC80 is 25% to 35% by weight.

11. The abrasive pad according to claim 7 or 8, wherein the abrasive layer comprises polypropylene glycol and polyether polycarbonate diol.

12. The abrasive pad of claim 11, wherein the polyether polycarbonate diol accounts for less than 80% of the total of the polypropylene glycol and the polyether polycarbonate diol.

13. An abrasive pad having an abrasive layer comprising a polyurethane resin foam, said polyurethane resin foam being derived from an isocyanate-terminated prepolymer and a hardener, wherein in the abrasive pad, The isocyanate-terminated prepolymer comprises structural units derived from polyisocyanate compounds and structural units derived from high molecular weight polyols. The structural units derived from high molecular weight polyols include at least polypropylene glycol structural units and polyether polycarbonate diol structural units. The polypropylene glycol structural units are less than 80% by weight relative to the structural units derived from high molecular weight polyols. The weight ratio of the amorphous phase in the polishing layer, measured by pulsed nuclear magnetic resonance at 80°C, is NC80 to NC40, which is 1.5 to 2.5 relative to the weight ratio of the amorphous phase in the polishing layer, measured by pulsed nuclear magnetic resonance at 40°C.

14. The abrasive pad according to claim 13, wherein the polypropylene glycol structural unit is 30% to 70% by weight relative to the structural unit derived from the high molecular weight polyol.

15. The abrasive pad according to claim 13 or 14, wherein the polyether polycarbonate diol structural unit is derived from polyether polycarbonate diol having a number average molecular weight of 600 to 2500.

16. A method for manufacturing an abrasive pad, comprising: manufacturing an abrasive pad having an abrasive layer comprising a polyurethane resin foam, the method comprising: A process of reacting a polyisocyanate compound with a high molecular weight polyol comprising at least polypropylene glycol and polyether polycarbonate diol to obtain an isocyanate-terminated prepolymer. The process of reacting the isocyanate-terminated prepolymer with a curing agent to obtain the polyurethane resin foam; and The process of molding the polyurethane resin foam and forming it into the shape of a polished layer, and The polypropylene glycol is less than 80% by weight relative to the total amount of the high molecular weight polyols. The weight ratio of the amorphous phase in the polishing layer, measured by pulsed nuclear magnetic resonance at 80°C, is NC80 to NC40, which is 1.5 to 2.5 relative to the weight ratio of the amorphous phase in the polishing layer, measured by pulsed nuclear magnetic resonance at 40°C.

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