JP2023506029A - Polishing Pad for Wafer Polishing Machine and its Manufacturing Apparatus and Manufacturing Method - Google Patents

Abstract

The present invention includes the steps of manufacturing a nonwoven pad, impregnating the nonwoven pad with polyurethane, and polishing the surface of the nonwoven pad impregnated with polyurethane, wherein the polyurethane impregnation and The surface polishing step provides a method of manufacturing a polishing pad in which the density ratio between the surface layer and the inside of the polishing pad is uniform. [Selection drawing] Fig. 3

Description

The present invention relates to a wafer polishing machine, and more particularly to a polishing pad used in the wafer polishing machine.

Single Crystal Silicon Ingots are generally grown and manufactured by the Czochralski method. In this method, polycrystalline silicon is melted in a crucible in a chamber, a single crystal seed crystal is dipped in the melted silicon, and a single crystal silicon ingot ( Hereafter, it is a method of growing into an ingot).

A single crystal silicon wafer manufacturing process includes a single crystal growing process for manufacturing an ingot using the above-described method, and a thin disk-shaped wafer by slicing the ingot. A slicing process to be acquired, an edge polishing process for processing the outer periphery to prevent damage or distortion of the wafer obtained by the slicing process, and damage due to mechanical processing remaining on the wafer. A lapping process for removing (damage) to improve the flatness of the wafer, a polishing process for mirror-finishing the wafer, and removing abrasives and foreign substances attached to the polished wafer. and a cleaning step.

In the wafer polishing process, both sides of the wafer can be polished simultaneously using a double side polishing apparatus (DSP).

FIG. 1 is a perspective view of a general wafer polisher.

As shown in FIG. 1, a typical wafer polishing apparatus 100 includes an upper surface plate 110, a lower surface plate 120, an upper pad (or upper polishing pad) 130, a lower pad (or lower polishing pad) 140, It includes carrier 150 , sun gear 160 , internal gear 170 and central shaft 180 .

The upper surface plate 110 and the lower surface plate 120 face each other and are rotatably arranged.

The upper pad 130 is arranged below the upper platen 110 and the lower pad 140 is arranged above the lower platen 120 . Upper and lower pads 130 and 140 are arranged facing each other inside the upper surface plate 110 and the lower surface plate 120 to polish the wafer W. As shown in FIG.

Each of the upper surface plate 110 and the lower surface plate 120 may have a disc shape, and the upper and lower pads 130 and 140 attached to the upper surface plate 110 and the lower surface plate 120 may also have a disc shape.

Sun gear 160 is provided on the outer circumference of central shaft 180 , and internal gear 170 is provided on the outer circumference of lower surface plate 120 . Internal gear 170 can rotate in the opposite direction to sun gear 160 .

Carrier 150 is disposed between upper pad 130 and lower pad 140 and can be rotated by rotation of sun gear 160 and internal gear 170 . In addition, the carrier 150 has an insertion hole into which the wafer W can be inserted and a slurry hole into which slurry can flow. The carrier 150 may have a disk shape with threads formed on the outer circumference.

A gear portion formed on the outer peripheral surface of the sun gear 160 and a gear portion formed on the inner surface of the internal gear 170 mesh with a gear 152 formed on the outer peripheral surface of the carrier 150 . Therefore, when the upper surface plate 110 and the lower surface plate 120 are rotated around the central axis 180 by a drive source (not shown), the carrier 150 rotates and revolves.

Although not shown, the top of the upper surface plate 110 may be provided with a plurality of slurry supply holes 190 through which nozzles for supplying slurry are installed.

In the general wafer polishing apparatus 100 having the above-described structure, when the wafer W is inserted into the insertion hole of the carrier 150 provided between the upper surface plate 110 and the lower surface plate 120, the wafer W is transferred to the upper surface plate. It rubs against upper and lower pads 130 and 140 attached to 110 and lower platen 120, respectively. Here, both surfaces of the plurality of wafers W mounted on the carrier 150 are friction-polished in a batch manner by slurry and polishing pads 130 and 140 supplied from the top of the upper platen 110 to the inside. That is, the wafer W is rubbed and polished by rotating the upper pad 130 of the upper platen 110 and the lower pad 140 of the lower platen 120 in opposite directions.

By the way, the polishing pads 130, 140 have their porous surfaces changed due to frequent friction with the wafer W, causing glazing in which the surface layer is clogged with slurry or polishing by-products. Such glazing reduces the coefficient of friction of the polishing pads 130 and 140, thereby deteriorating the polishing quality of the wafer.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a polishing pad for a wafer polishing apparatus, an apparatus for manufacturing the same, and a method for manufacturing the same, which can prevent glazing from occurring during the wafer polishing process and improve the flatness quality of the wafer.

The present invention includes the steps of manufacturing a nonwoven pad, impregnating the nonwoven pad with polyurethane, and polishing the surface of the nonwoven pad impregnated with polyurethane, wherein the polyurethane impregnation and The surface polishing step provides a method of manufacturing a polishing pad for a wafer polishing apparatus in which the density ratio between the surface layer and the inside of the polishing pad is uniform.

The polyurethane impregnation step includes a pretreatment step of pretreating the nonwoven pad, a primary drying step of drying moisture in the nonwoven pad, an impregnation step of soaking the nonwoven pad in polyurethane, and an impregnation step of impregnating the nonwoven pad with polyurethane. A secondary drying step of drying the polyurethane and a compression step of compressing the polyurethane impregnated nonwoven pad may be included.

The impregnation step may perform at least two polyurethane impregnation processes.

The impregnation step may include a primary impregnation process of impregnating hydrophilic polyurethane and a secondary impregnation process of impregnating hydrophobic polyurethane.

The surface layer of the polishing pad may be buffed so that the density ratio between the polyurethane-containing porous layer and the polyurethane-free porous layer is 1:1.

The thickness of the non-woven pad may be 4 mm to 6 mm, and the thickness of the non-woven pad removed during the buffing may be 2.5 mm to 3.5 mm.

The polishing pad may have a total density of 0.44-0.55 g/cm ³ .

On the other hand, the present invention includes a non-woven pad manufacturing department that manufactures a non-woven pad, a polyurethane impregnating department that impregnates the non-woven fabric pad with polyurethane, and a surface polishing department that polishes the surface of the non-woven pad impregnated with polyurethane, The polyurethane impregnation unit provides an apparatus for manufacturing a polishing pad for a wafer polishing apparatus, including a primary polyurethane water tank containing hydrophilic polyurethane and a secondary polyurethane water tank containing hydrophobic polyurethane.

The surface polishing portion can be buffed so that the density ratio of the polyurethane-containing porous layer and the polyurethane-free porous layer on the surface layer of the polishing pad is 1:1.

The thickness of the non-woven pad may be 4 mm to 6 mm, and the thickness of the non-woven pad removed during the buffing may be 2.5 mm to 3.5 mm.

The present invention provides a polishing pad for a wafer polishing apparatus manufactured by any of the manufacturing methods or manufacturing apparatuses described above.

According to the polishing pad for a wafer polishing apparatus and the manufacturing apparatus and manufacturing method thereof according to the present invention, the density of the polyurethane impregnated in the surface layer of the polishing pad is made uniform, thereby preventing glazing that occurs during the wafer polishing process. Wafer flatness quality can be improved.

Also, the polishing pad of the present invention is: The roughness of the surface layer of the pad is maintained at a high level, thereby suppressing the decrease in the removal rate due to the increase in the use time of the conventional pad, thereby extending the life of the pad.

1 is a perspective view of a typical wafer polishing apparatus; FIG.

1 is a schematic configuration diagram of an apparatus for manufacturing a wafer polishing pad according to an embodiment of the present invention; FIG.

1 is a flow chart of a method for manufacturing a wafer polishing pad according to one embodiment of the present invention;

FIG. 4 is a process chart showing steps of manufacturing a polishing pad by the manufacturing method of FIG. 3 ; FIG. 4 is a process chart showing steps of manufacturing a polishing pad by the manufacturing method of FIG. 3 ;

FIG. 4 is a cross-sectional view of a polishing pad containing polyurethane (a) before buffing and (b) after buffing.

4 is a graph showing the density depending on the thickness of a polishing pad of an example of the present invention and a polishing pad of a comparative example;

FIG. 8 is a front view of CT imaging showing a tomographic state of the polishing pad of FIG. 7 with a thickness of 100 μm.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be made clearer by the following description of the accompanying drawings and examples. In the description of the embodiments, each layer (film), region, pattern or structure is formed "on" or "under" the substrate, each layer (film), region, pad or pattern. , "on" and "under" include anything that is formed "directly" or "indirectly through another layer." In addition, the reference to the top or bottom of each layer will be explained with reference to the drawings.

In the drawings, sizes are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not directly reflect the actual size. Also, like reference numbers refer to like elements throughout the description of the drawings. An embodiment will be described below with reference to the accompanying drawings.

FIG. 2 is a schematic configuration diagram of a wafer polishing pad manufacturing apparatus according to an embodiment of the present invention, FIG. 3 is a flow chart of a wafer polishing pad manufacturing method according to an embodiment of the present invention, and FIGS. It is process drawing which shows the process which manufactures a polishing pad by the manufacturing method of FIG. 3, and FIG. 6 is sectional drawing (a) before buffing and (b) after buffing of the polishing pad containing polyurethane.

As shown in FIG. 2, the apparatus for manufacturing a wafer polishing pad according to an embodiment of the present invention comprises a nonwoven pad manufacturing unit 1, a polyurethane impregnating unit 2, a surface polishing unit 3, and a tape attaching and cutting unit 4. can be done.

Here, each section 1, 2, 3, 4 can be a combined set of equipment, each section 1, 2, 3, 4 constituting a single connected manufacturing route. be able to.

The non-woven pad manufacturing section 1 includes a series of devices for manufacturing non-woven pads, which are the main materials used for polishing pads. For example, as shown in FIG. 4, the non-woven fabric pad manufacturing unit 1 includes a supply unit 10 that supplies the fiber C mass, a pressure bonding unit 20 that compresses the fiber C mass, a bonding unit 30 that performs a needle punching process, and a A punching portion 40 may be included.

The polyurethane impregnation section 2 includes a series of devices for impregnating and coating the non-woven pad with polyurethane. For example, the polyurethane impregnated part 2 includes a pretreatment water tank 50, a primary drying part 60, a primary polyurethane water tank 70, a secondary polyurethane water tank 80, a secondary drying part 100, and a pressing roller 110, as shown in FIG. be able to.

The surface polishing section 3 includes a series of devices for removing the surface layer of the non-woven pad impregnated with polyurethane. For example, the surface polishing unit 3 may include sandpaper 120 for buffing, as shown in FIG.

The tape applying and cutting unit 4 includes a series of devices for applying a double-sided tape T to one side of the buffed polishing pad and cutting it into circular pads.

For example, the tape applying and cutting section 4 can include a cutter section 130, a tape applying section 140, a crimping section 150, a shape cutting section 160, and a packaging inspection section 170, as shown in FIG.

Hereinafter, a polishing pad using the apparatus for manufacturing a wafer polishing pad according to an embodiment of the present invention including the above-described structure and a method for manufacturing the same will be described in detail.

As shown in FIG. 3, a polishing pad for a wafer polishing apparatus (hereinafter referred to as a polishing pad) according to an embodiment of the present invention comprises a non-woven pad manufacturing step S100, a polyurethane impregnation step (S200), a surface polishing step (S300), and a tape attachment. and a cutting step (S400) and a polishing pad mounting step (S500).

1) Non-woven fabric pad manufacturing step (Non-woven Fabric Manufacturing, S100)

An example polishing pad according to this embodiment is manufactured in the form of a pad by a non-woven fabric manufacturing step. Non-Woven Fabric refers to a pad that is not loomed. It is made by binding fibers to form a direct fabric, and is also called a bonded fabric. Materials such as polyester, viscose rayon, nylon, polypropylene, cotton, linen, wool, asbestos, glass fiber, and acetate can be selected as the fiber.

Non-woven fabrics are classified into two types according to the manufacturing method: a dry-laid non-woven fabric manufacturing method that does not use water, and a wet-laid non-woven fabric manufacturing method that uses water. be. A dry nonwoven fabric manufacturing method may be used in the nonwoven pad manufacturing step S100 according to the present embodiment.

More specifically, in the non-woven pad manufacturing step S100, as shown in (1) of FIG. The supplied fibers C are pressed to produce a web W (a thin spread of fibers); A non-woven pad F is manufactured by punching with a niddle. The polyurethane impregnation step (S200) is performed to the manufactured non-woven pad F in order to provide the physical properties that the polishing pad should have.

2) Polyurethane Impregnating (S200)

The step of impregnating with polyurethane (S200) includes a process of impregnating the non-woven fabric pad F produced in step 1) (S100) in the polyurethane water tank 70 for a certain period of time. The non-woven fabric pad F has a large number of pores, that is, a pore layer, not only on the surface but also inside. The polyurethane PU can penetrate into the porous layer of the non-woven pad F and provide the necessary physical properties for the polishing pad.

Polyurethane PUs are compounds produced by the combination of polyols and isocyanates. That is, it is a polymer compound in which urethane bonds are repeatedly included in the polymer chain, and epoxy, polyester, phenol, etc. correspond to this compound.

The polyurethane impregnation step (S200) includes i) pretreatment, ii) first drying, iii) impregnating, and iv) secondary drying ( 2nd drying), and v) a pressing process.

The pretreatment and drying process are steps performed before the impregnation of the polyurethane PU to facilitate the impregnation process of the polyurethane PU. The pretreatment process may include a process of immersing the nonwoven pad F in a pretreatment water tank 50 containing cleaning liquid or chemicals. The non-woven fabric pad F manufactured in step 1) (S100) may be moved into the pretreatment water tank 50 by a roller R. The non-woven pad F that has undergone the pretreatment process can proceed to the primary drying process by the roller R.

The primary drying process may be a process of drying the non-woven fabric pad F soaked in cleaning liquid or chemicals. For example, the primary drying process can be performed by the primary drying unit 60 that can evaporate cleaning liquid or chemicals using a heater, fan, or the like.

The impregnation process is a process of immersing the non-woven fabric pad F in a polyurethane water tank 70 containing polyurethane PU. Polyurethane PUs are produced by mixing two or more liquids and their properties depend on the type of reactants isocyanates and polyols. The long bonds contained in the polyol help make it a soft elastomeric polymer, and the many bonds make it a hard polymer. By maintaining an intermediate length between the two bonds, it is possible to maintain adequate stiffness while having great stretchability. That is, when the polyurethane PU is produced, the ratio of the soft segment and the hard segment, which are constituent materials, can be adjusted to adjust the elasticity and softness to suit the application. The higher the soft segment ratio, the lower the hardness and the greater the elasticity.

By controlling the conditions of the polyurethane PU impregnation process, the mass, volume, thickness, etc. of the polyurethane PU contained in the non-woven fabric pad F can be changed. Here, the conditions can be the impregnation time, the concentration of the polyurethane PU, the number of times of impregnation, the movement speed of the nonwoven fabric pad F, and the like.

In this embodiment, glazing can be improved by uniforming the density of polyurethane PU on the surface and inside of the polishing pad (Pad) to improve air permeability. For this purpose, at least one of the following homogenization conditions may be included in the polyurethane impregnation process.

First, in the process of impregnating polyurethane, the non-woven fabric pad F containing polyurethane PU can be dipped in a secondary polyurethane water tank 80 . That is, the polyurethane impregnation process may be performed at least twice. Also, the non-woven pad F containing polyurethane PU can be further submerged in a tertiary polyurethane water bath 90 or cleaning bath 90 for additional polyurethane impregnation or cleaning, if desired.

Here, both the polyurethane of the primary polyurethane water tank 70 and the secondary polyurethane water tank 80 may have hydrophobic properties. That is, it can have the property of being immiscible with water.

Also, the primary polyurethane water tank 70 can be filled with a hydrophilic polyurethane that is friendly with water, and the secondary polyurethane water tank 80 can be filled with a hydrophobic polyurethane. Here, if the primary polyurethane water tank 70 is hydrophilic, the polyurethane can be impregnated while being more smoothly moved from the surface to the inside of the non-woven fabric pad F, compared to the hydrophobic case, when impregnated with polyurethane. .

Second, the thickness of the non-woven pad used for polyurethane impregnation can be made thicker. For example, the polyurethane impregnation step (S200) can be performed by applying the 5 mm thick non-woven pad manufactured in the non-woven fabric manufacturing step (S100) (the conventional non-woven pad has a thickness of 2.3 mm). ). In this case, the buffing thickness can be increased to 2.7 mm or more compared to the conventional method in the surface polishing step (S300), which will be described later.

That is, in an embodiment, the thickness of the non-woven pad can be between 4 mm and 6 mm, and the thickness of the non-woven pad removed during buffing can be between 2.5 mm and 3.5 mm.

After that, a secondary drying process can be performed. For example, the secondary drying process can be performed by the secondary drying unit 100 that can dry the polyurethane PU using a heater, a fan, or the like.

Next, the non-woven fabric pad UF containing polyurethane PU is passed through the pressing roller 110 to perform a compression process so that the polyurethane PU is deeply contained in the interior of the non-woven fabric pad UF.

3) Surface polishing (S300)

A surface polishing step is performed (S300) on the non-woven pad UF that has undergone the polyurethane impregnation step (S200). In the surface polishing step (S300), sanding or buffing is performed using sandpaper to remove contaminants from the surface and bottom of the non-woven pad UF. In addition, the thickness of the polishing pad (Pad) and the ratio of surface voids can be adjusted by the surface polishing step (S300).

As shown in FIG. 6(a), the polyurethane PU impregnation density in the polishing pad (Pad) is high (High) at the surface layer and decreases (Low) toward the inside. Therefore, due to the high polyurethane PU density on the surface of the polishing pad, the slurry that flows into the surface of the polishing pad during wafer polishing does not move to the inside and adheres to the surface to generate glazing. .

In order to improve such problems, in the surface polishing step (S300), as shown in FIGS. By removing a part, the pores P inside the surface layer can be further exposed. Therefore, since the polishing pad can further increase the ratio of the portion impregnated with polyurethane PU in the surface layer portion and the inner portion that is not impregnated, the slurry moves to the inside of the polishing pad, and the surface can be prevented from sticking to the

and the total density of the polishing pad (Pad) may be 0.44-0.55 g/cm ³ , and the compressibility of the polishing pad (Pad) may be 1.9-2.0%, The hardness of the polishing pad (Pad) can be 88 AskerC. That is, even if the polyurethane PU impregnation density for the surface layer of the polishing pad (Pad) is adjusted, the basic physical properties required for the polishing pad (Pad) can be maintained.

4) Tape pasting and cutting (S400)

The tape attaching and cutting step (S400) is a step of attaching a double-sided tape T to one surface of the polishing pad UF impregnated with polyurethane PU and cutting it into a circular pad shape.

More specifically, in the tape attaching and cutting step (S400), as shown in (4) of FIG. ), ii) the tape attaching unit 140 attaches the double-sided tape T to one surface of the polishing pad UF (PSA prepasting), iii) the pressing unit 150 presses the double-sided tape T (PAS pasting, pressing), and iv) shape cutting. The unit 160 cuts the polishing pad UF to which the double-sided tape T is crimped into a certain shape (for example, a circle of the size of the platen); v) The packaging inspection unit 170 inspects the product and packages it with wrapping paper. (Inspection, Shipping).

5) Mounting of the Polishing Pad (S500)

The polishing pad UF packaged in the 4th step (S400) is subjected to the wafer polishing process together with the slurry after attaching one side of the double-sided tape T to the platen of the wafer polishing machine.

FIG. 7 is a graph showing the density depending on the thickness of the polishing pad of one example of the present invention and the polishing pad of the comparative example.

As shown in FIG. 7, the polishing pad of the example was manufactured by the manufacturing apparatus and manufacturing method described above so that the polyurethane impregnation ratio was uniform. It can be seen that it has an average Density value regardless of . On the other hand, the polishing pad of the comparative example has a high density in the front surface portion and the surface layer portion forming the bottom portion.

As described above, in the conventional (comparative) polishing pad, the slurry flowing into the surface of the pad during the polishing process does not move into the pad due to the high density of the surface, so the glazing adheres to the surface of the pad. caused

The polishing pad of the present invention has a uniform density on the surface and inside of the pad, and can improve slurry flow to the inside of the polishing pad.

FIG. 8 is a CT front view showing a tomographic state of the polishing pad of FIG. 7 with a thickness of 100 μm.

Generally, it was observed that the glazing that occurs in the polishing pad in the comparative example was formed from the surface of the polishing pad to a depth of 300 μm. That is, the thickness of the glazing layer can be formed from the front surface of the polishing pad to the inside of 300 μm.

As shown in FIG. 8, as can be seen from the photographing results of the 100 μm-thick layers of the present example and the comparative example, the comparative example has more glazing areas (white spots, glazing areas). I understand.

In this way, the polishing pad of this example has uniform density on the surface and inside of the pad, and the slurry smoothly flows into the inside of the pad, so that the effect of controlling the glazing area from the surface layer to a depth of 100 μm is obtained. can be provided.

However, according to the polishing pad for a wafer polishing apparatus and the method of manufacturing the same according to the present invention, the density of the polyurethane exposed on the surface of the polishing pad is made uniform, thereby preventing glazing that occurs during the wafer polishing process. can improve the flatness quality of

In addition, the polishing pad of the present invention maintains the roughness of the surface layer of the pad at a high level, thereby suppressing the decrease in the removal rate due to the increase in the use time of the conventional pad. That is, the life of the polishing pad can be extended.

The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to a single embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified in other embodiments by those who have ordinary knowledge in the field to which the embodiment belongs. Accordingly, all such combinations and variations should be construed as included within the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention is applicable to a polishing pad for a wafer polishing apparatus, an apparatus and method for manufacturing a wafer polishing pad, and the like.

Claims (11)

producing a nonwoven pad;
a polyurethane impregnation step of impregnating the non-woven pad with polyurethane;
a surface polishing step of polishing the surface of the polyurethane impregnated nonwoven pad;
The method of manufacturing a polishing pad for a wafer polishing apparatus, wherein the polyurethane impregnation step and the surface polishing step make the density ratio between the surface layer and the inside of the polishing pad uniform. The polyurethane impregnation step comprises:
a pretreatment step of pretreating the nonwoven pad;
a primary drying step of drying moisture of the non-woven fabric pad;
an impregnation step of soaking the non-woven pad in polyurethane;
a secondary drying step of drying the polyurethane impregnated in the nonwoven pad;
2. The method of manufacturing a polishing pad for a wafer polishing apparatus according to claim 1, further comprising a compressing step of compressing the nonwoven pad impregnated with polyurethane. 3. The method of claim 2, wherein the impregnating step includes at least two polyurethane impregnation processes. The impregnation step includes:
A primary impregnation step of impregnating hydrophilic polyurethane;
4. The method of manufacturing a polishing pad for a wafer polishing apparatus according to claim 3, further comprising a secondary impregnation step of impregnating the hydrophobic polyurethane. 5. The polishing pad for a wafer polishing apparatus according to claim 4, wherein the surface layer of said polishing pad is buffed so that the density ratio of said polyurethane-containing porous layer to said polyurethane-free porous layer is 1:1. Production method. The non-woven fabric pad has a thickness of 4 mm to 6 mm,
6. The method of manufacturing a polishing pad for a wafer polishing apparatus according to claim 5, wherein the thickness of said non-woven fabric pad removed during said buffing is 2.5 mm to 3.5 mm. 7. The method of manufacturing a polishing pad for a wafer polishing apparatus according to claim 6, wherein the polishing pad has a total density of 0.44-0.55 g/cm ³ . a non-woven pad manufacturing department that manufactures non-woven pads;
a polyurethane-impregnated part for impregnating the non-woven fabric pad with polyurethane;
a surface polishing unit for polishing the surface of the non-woven fabric pad impregnated with polyurethane;
The polyurethane-impregnated part is
a primary polyurethane water tank containing hydrophilic polyurethane;
and a secondary polyurethane water bath containing hydrophobic polyurethane. 9. The wafer according to claim 8, wherein the surface polishing part buffs the surface layer of the polishing pad so that the density ratio of the porous layer containing the polyurethane and the porous layer not containing the polyurethane is 1:1. Equipment for manufacturing polishing pads for polishing equipment. 10. The polishing for a wafer polishing apparatus according to claim 9, wherein the thickness of said non-woven fabric pad is 4 mm to 6 mm, and the thickness of said non-woven fabric pad removed during said buffing is 2.5 mm to 3.5 mm. Pad manufacturing equipment. A polishing pad for a wafer polishing apparatus manufactured by the manufacturing method or manufacturing apparatus according to any one of claims 1 to 10.

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