JP2015168479A - Abrasive pad packing object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abrasive pad packing object, capable of protecting a surface of the abrasive pad during transport and storage, suppressing deformation of the abrasive pad, and reducing cost and waste matters compared with a case that the abrasive pad is packed one by one, without changing a material forming the abrasive pad.SOLUTION: An abrasive pad packing object 6 formed by packing plural abrasive pads with a packing material 5 is packed in a manner that abrasive surfaces 4, 4 which are surfaces of abrasive layers 1, 1 of two abrasive pads relatively contact, as much as possible.

Description

  The present invention relates to a polishing pad packing method and a packing material preferably used for forming a flat surface in a semiconductor, a dielectric / metal composite, an integrated circuit, and the like.

  Large scale integrated circuits (LSIs) typified by semiconductor memories have been integrated year by year, and accordingly, the manufacturing technology of large scale integrated circuits has also been increased in density. Furthermore, with this increase in density, the number of stacked semiconductor device manufacturing locations has also increased. Due to the increase in the number of stacked layers, unevenness of the main surface of the semiconductor wafer caused by stacking that has not been a problem in the past has become a problem. As a method for flattening the unevenness, chemical mechanical polishing (hereinafter referred to as CMP: CMP: Chemical Mechanical Polishing) has come to be used.

  In general, a CMP apparatus includes a polishing head that holds a semiconductor wafer that is an object to be polished, a polishing pad that performs a polishing process on the object to be polished, and a polishing surface plate that holds the polishing pad. Then, the polishing process of the semiconductor wafer is performed by using a polishing slurry (hereinafter referred to as a slurry) made of an abrasive and a chemical solution, and polishing the semiconductor wafer by moving the semiconductor wafer and the polishing pad relative to each other to flatten the surface of the semiconductor wafer. It is. Typical characteristics required for CMP include uniformly polishing the surface of the object to be polished, flattening the surface of the object to be polished, removing the object to be polished at a high polishing rate, It is required to suppress the occurrence of fine polishing scratches called scratches generated on the surface of the steel.

  In order to obtain these characteristics, a polishing pad is generally used which is composed of a foam material having elasticity or compressibility, or a laminate using the same (for example, Patent Document 1). Further, since these polishing pads are used in a clean room, they are generally packed with an antistatic film or the like in order to prevent the adhesion of foreign matters (for example, Patent Document 2). Patent Document 3 discloses a technique for packaging in an environment with a small amount of suspended particles, preventing adhesion of foreign matters to the surface of the polishing pad, and suppressing scratches generated on the surface of the object to be polished.

However, although attention has been paid to preventing adhesion of foreign substances in these techniques, there are still the following problems with respect to transportation and storage.
(Problem 1) When the surface of the polishing pad is exposed to ultraviolet rays during transportation or storage, the surface of the polishing pad turns yellow, changes its physical properties, reduces the polishing rate, or causes fine polishing scratches called scratches. It may affect the polishing characteristics.
(Problem 2) If the polishing pad is bent during transportation or storage, and the polishing pad is bent, the flatness of the polishing pad deteriorates, so that the in-plane uniformity of the object to be polished deteriorates or scratches are For example, the polishing characteristics deteriorate.
(Problem 3) Packing the polishing pads one by one not only increases the cost of the packing material, but also generates a lot of waste during use.

  In order to solve these problems, Patent Document 4 and Patent Document 5 disclose a technique of packaging with a packaging material having a low ultraviolet transmittance, and attempts have been made to solve the above (Problem 1). Yes. Patent Document 6 discloses a technique for making a set of two polishing pads by sharing the release paper on the back of the polishing pad with two polishing pads, and making the polishing pad difficult to bend by increasing the rigidity of the polishing pad. Attempts have been made to solve the above (Problem 2) and (Problem 3).

JP-A-6-21028 Japanese Patent Laid-Open No. 2005-103702 Japanese Patent Laid-Open No. 2005-103702 JP 2007-39096 A JP 2004-259728 A JP 2005-262424 A

Regarding the transportation and storage of polishing pads, in addition to the above problems,
(Problem 4) When an impact is applied to the surface of the polishing pad before use, the surface of the polishing pad is scratched or deformed, and the polishing characteristics are deteriorated as in (Problem 2) described above.
There is a problem. However, none of the above prior art documents mentioned the above (Problem 4), and no method for solving the problem 4 was shown.

  The present invention protects the surface of the polishing pad from changes in physical properties due to yellowing and scratches and deformation due to impact during transportation and storage without changing the configuration of the polishing pad, and further suppresses deformation of the polishing pad, And it aims at providing the polishing pad package which reduces a cost and a waste compared with the packing of every polishing pad.

  The present invention for solving the above-mentioned problems is a polishing pad packaged product in which a plurality of polishing pads are packed, and is packed so that the polishing surfaces of two polishing pads are in contact with each other as much as possible. This is a polishing pad package characterized by the above.

  According to the present invention, during transportation or storage of the polishing pad, the surface of the polishing pad is exposed to ultraviolet rays to change its physical properties, or the polishing pad is vertically placed and deformed. Thus, it is possible to suppress the surface of the polishing pad from being scratched or deformed.

It is a cross-sectional schematic diagram of a polishing pad package in a state where two polishing pads are overlapped so that the polishing surfaces are in contact with each other. It is a cross-sectional schematic diagram of the conventional polishing pad package. It is a cross-sectional schematic diagram of the polishing pad packaged object which piled up two sets of polishing pads of the state which piled up two polishing pads so that a polishing surface might mutually contact, and was packed with the bag-shaped packing material. FIG. 3 is a schematic cross-sectional view of a polishing pad package in which two polishing pads are stacked such that the polishing surfaces are in contact with each other and stacked in a direction in which the polishing surface does not face the outer surface. . FIG. 2 is a schematic cross-sectional view of a polishing pad package in which three of the polishing pad packages in FIG. 1 are further secondary packed. It is a schematic diagram which shows the state which aligned and overlap | superposed the position of the groove | channel formed in each polishing surface of the polishing pad which a polishing surface opposes. It is a schematic diagram which shows the state which shifted and overlap | superposed the position of the groove | channel formed in each polishing surface of the polishing pad which a polishing surface opposes. It is a schematic diagram which shows the angle which the groove | channel formed in each polishing surface of the polishing pad which a polishing surface opposes comprises.

  In the present invention, as shown in FIG. 1, as much as possible, the polishing surfaces 4 of the polishing pad are overlapped and packed so as to be in contact with each other. By packing in this way, the polishing surface of the polishing pad does not face the outer surface via the packing material 5. For this reason, it is possible to prevent the surface of the polishing pad from being yellowed by being exposed to ultraviolet rays, or from being damaged or deformed due to an external impact. That is, the above (Problem 1) and (Problem 4) can be solved.

  The polishing layer of the polishing pad is often formed of polyurethane foam or the like, and the rigidity against deformation is not sufficiently high. Therefore, when it is placed vertically during transportation or storage, it tends to bend and deform. In order to solve this problem, in the present invention, the polishing surfaces of the polishing pads are overlapped so as to be in contact with each other, and a plurality of polishing pads are packed together. By packing in this way, the thickness of the polishing pad is increased compared to packing with one polishing pad, and the rigidity of the polishing pad package 6 is increased, so that deformation of the polishing pad can be suppressed. . That is, the above (Problem 2) can be solved.

  In the present invention, a plurality of polishing pads are packed together in one packing material. Therefore, compared with the case where the polishing pads are packed one by one, the cost for the packing material and the waste when using the polishing pad can be reduced. That is, the above (Problem 3) can be solved.

  In the present invention, “superimposing so that the polishing surfaces of the two polishing pads are in contact with each other as much as possible” specifically means superimposing as follows. When four or more even number of polishing pads are put in one packing material, as shown in FIG. 3, two sets of polishing pads in which the polishing surfaces 4 are opposed to each other are stacked and packed. It ’s fine. When putting three or more odd-numbered polishing pads in one bag, as shown in FIG. 4, they are stacked in the same manner as when packing the even-numbered one, and one polishing that cannot be stacked as a set of two. The pads are stacked and packed in a direction or position where the polishing surface 4 does not face the outer surface. If packing is performed in this manner, the polishing surface does not face the outer surface through the packing material 5, so that yellowing of the polishing surface and damage due to collision can be prevented. The number of polishing pads to be packed with one packing material is not particularly limited as long as it is 2 or more, but if it is an even number, it must be an even number because the polishing surfaces can be overlapped with each other on all polishing pads. Is preferred.

  As shown in FIG. 1, a polishing pad package 6 in which two polishing pads are grouped together and packed with a packing material 5 so that the polishing surfaces are in contact with each other, that is, a book containing two sheets. The polishing pad package 6 of the invention is a particularly preferred embodiment. When packed in this way, the polishing surfaces of both polishing pads come into contact with each other and the polishing surfaces are protected, so that the surface of the polishing layer is prevented from adhering to foreign materials, and scratches generated on the object caused by foreign materials are suppressed. it can. Moreover, since the back surface of each polishing pad faces the outer surface, it is possible to see the label attached to the back surface of the pad without opening the packing material 5. Therefore, when checking the lot number and model of the polishing pad during inventory management or the like during storage, it is not necessary to open the packing material 5 and take out the polishing pad inside. In addition, since the polishing pad is exposed to the outside air and the opportunity for foreign matters to adhere can be eliminated, the generation of scratches on the object to be polished caused by the foreign matters can be suppressed.

  One or a plurality of polishing pad packages 6 may be collected and further packed with a secondary packing material. For example, as shown in FIG. 1, a plurality of polishing pad primary packing materials 7 packed together by a packing material 5 in a set of two sheets are collected and packed with another secondary packing material 9 as shown in FIG. be able to. By performing secondary packaging, the set of two polishing pads is less likely to be displaced and the rigidity of the polishing pad is higher, so it is not only difficult to deform during storage or transportation, but if you unpack the secondary packaging, Since the label on the back side of the pad can be confirmed without unpacking the primary packaging, the risk of foreign matter adhering to the polishing pad when checking contents such as inventory management can be greatly reduced. In the present specification, a package including such a secondary package may be referred to as a “polishing pad package”.

  Grooves are generally formed on the surface of the polishing layer 1 of the polishing pad in order to hold and discharge the slurry. Since the thickness of the polishing pad is reduced at the groove portion, the rigidity of the pad is lowered. When the groove is placed vertically during transportation or storage, the groove portion tends to be deformed particularly. As shown in FIG. 6, when the polishing surfaces 4 are overlapped so as to be in contact with each other, if the positions of the grooves formed on the respective polishing surfaces are overlapped, the rigidity of the groove portion is higher than that of the other portions. Since it will fall, it will become still easier to deform | transform. As shown in FIG. 7, by shifting the position of the grooves formed on each polishing surface 4, it is possible to prevent the rigidity of the polishing pad from being locally lowered, and to be placed vertically during transportation and storage. Even if it is done, it becomes difficult to deform the polishing pad. In particular, a polishing pad having a groove pattern including a linear groove such as a lattice-like groove is easily deformed at the linear groove portion, so the position of the groove between the polishing pads that are overlapped so that the polishing surfaces are opposed to each other is determined. Shifting is particularly effective.

  Here, in the case of packing a polishing pad having a linear groove on the polishing surface, when the two polishing pads stacked with the polishing surface facing each other are used as polishing pad A and polishing pad B, respectively, As shown in FIG. 8, the smallest angle among the angles formed by the groove 11 formed on the polishing surface of the polishing pad A10 and the groove 21 formed on the polishing surface of the polishing pad B20 is referred to as a groove shift angle α. In this case (the groove misalignment angle is 45 ° or less), the groove misalignment angle α is preferably 10 ° or more, more preferably 20 ° or more, and most preferably 45 °. When the groove misalignment angle is less than 10 °, the groove positions of the superimposed polishing pads are close to each other, and therefore, the groove tends to bend at the groove position.

  Another effect of overlapping the polishing surfaces of the polishing pads so as to be in contact with each other is that the warping of the polishing pads can be canceled and warpage deformation can be suppressed. The polishing pad includes a polishing layer 1 for polishing the object to be polished, a cushion layer 2 for enhancing the effect of uniformly polishing the surface of the object to be polished, a back surface tape 3 for fixing the polishing pad to the polishing machine surface plate, and the like. Is generally laminated. In such a polishing pad, since layers having different physical properties are laminated, the polishing pad may be warped due to the difference in expansion or contraction amount of each layer. If the polishing pads are stacked in the same direction, the warping direction will be the same for all pads. Since the directions are opposite to each other, an effect of canceling the warpage is generated, and warpage deformation of the polishing pad can be suppressed.

  In the packing material for packing the polishing pad, it is preferable to remove the gas as much as possible and to bring the polishing pads into close contact with each other because the rigidity of the polishing pad package is further increased. As an example of such a packing method, there is a method of evacuating the gas in the packing material and then sealing the opening.

  Although the packing material 5 and the secondary packing material 9 used for this invention are not specifically limited, It is preferable that it is a bag-shaped packing material. The bag-shaped packing material is not limited to a bag-shaped packing material with one side open, and for example, a polishing pad is sandwiched between folded film-like materials, and the three open sides are sealed and sealed. Packing the polishing pad, packing the polishing pad by sandwiching the polishing pad between two film-like materials, fusing the periphery, etc., and wrapping the polishing pad with film-like material Is also included.

  The material of the packaging material and secondary packaging material of the present invention is not particularly limited, polyethylene, polypropylene, nylon, polyester, polystyrene, polyvinyl chloride, polyvinylidene fluoride, polycarbonate, polyamide, polyacetal, polyimide, epoxy resin, Examples include unsaturated polyester resin, melamine resin, PVA, phenol resin, ABS resin, natural rubber, polyurethane rubber, various rubbers such as silicone rubber. These may be used alone or in combination of two or more. In addition, an inorganic material may be coated on the material of the bag-shaped packing material in order to improve gas barrier properties, prevent ultraviolet rays, and prevent charging. Examples of such an inorganic material include metal oxides such as silica, alumina, and titanium oxide.

  In order to confirm the description of the label on the back surface of the polishing pad through the packing material, the packing material preferably has a visible light transmittance, and a preferable light transmittance at a wavelength of 550 nm is 5% or more, and a more preferable light beam. The transmittance is 10% or more. If the light transmittance at a wavelength of 550 nm is less than 5%, the visibility of characters deteriorates, which is not preferable.

  In the present invention, since the polishing surface of the polishing pad does not face the outer surface through the packing material, it is possible to prevent the polishing pad surface from being exposed to ultraviolet rays and yellowing to change the physical properties of the polishing layer surface, In addition to the surface of the polishing pad, the packing material is preferably a material that blocks ultraviolet rays in order to suppress deterioration due to ultraviolet rays, and is preferably a material having a light transmittance of 50% or less at a wavelength of 200 to 380 nm.

Usually, since the polishing pad is used in a clean room, it is preferable to pack the polishing pad with a packing material in an atmosphere with a small amount of suspended particles. An environment in which the amount of floating particles of 0.5 μm or more is 1000 particles / ft ³ or less is preferable because foreign matter can be prevented from adhering to the polishing pad.

  The polishing pad package of the present invention can be further prevented from being damaged during transportation or storage by packing with a packing material such as a cardboard box or a cardboard board. Examples of the cardboard material include paper and various resins such as polypropylene and polycarbonate.

  The polishing pad package of the present invention includes, for example, polyethylene, polypropylene, polyester, polyurethane, polyurea, polystyrene, polyvinyl chloride, polyvinylidene fluoride, polymethyl methacrylate, polycarbonate, polyamide, polyacetal, polyimide, epoxy resin, and unsaturated polyester resin. , Melamine resin, phenol resin, ABS resin, bakelite, various laminates such as epoxy resin / paper, epoxy resin / fiber, FRP, natural rubber, neoprene rubber, chloroprene rubber, butadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, ethylene It is particularly effective for packing polishing pads made of various rubbers such as propylene rubber, silicone rubber and fluoro rubber. Among these, a polishing pad having a polyurethane foam polishing layer is subject to yellowing of the polishing layer surface due to ultraviolet rays and changes in physical properties. Also, since the rigidity is low, the polishing pad is easily deformed. In this case, the polishing pad package of the present invention is particularly effective.

  Hereinafter, the details of the present invention will be described with reference to examples. Various evaluations of the polishing pad were performed as follows.

a. Micro-rubber A hardness of polishing layer It was measured with a micro-rubber A hardness meter “MD-1” (manufactured by Kobunshi Keiki Co., Ltd.).

b. Polishing layer density Measured by the method described in JIS K7222.

c. Average bubble diameter of polishing layer The average bubble diameter is the number of bubbles observed in one field of view when a sample cross section is observed with an objective lens 20 times (observation magnification 400 times) with an ultra-deep microscope of Keyence VK-8500. A circular bubble excluding bubbles observed in a circular shape lacking at the edge of the field of view was measured for the equivalent circle diameter from the cross-sectional area with an image processing apparatus, and the calculated number average value was taken as the average bubble diameter.

d. Measurement of light transmittance Using a spectrophotometer “U-2000” (manufactured by Hitachi, Ltd.), measurement was performed at a measurement wavelength range of 200 to 700 nm and a scan speed of 200 nm / min.

e. Preparation of Polishing Pad Polyether polyol: “SANNICS FA-909” (manufactured by Sanyo Chemical Industries) 100 parts by weight, chain extender: 8 parts by weight of monoethylene glycol, amine catalyst: “Dabco” 33 LV "(manufactured by Air Products Japan) 1.95 parts by weight, amine catalyst:" Toyocat ET "(manufactured by Tosoh) 0.14 parts by weight, silicone foam stabilizer:" TEGOSTAB B8462 "(manufactured by Th. Goldschmidt AG) 1 weight Part, foaming agent: A liquid formed by mixing 0.55 parts by weight of water, and B liquid consisting of 96.2 parts by weight of isocyanate: “Sunfoam NC-703” maintained at a liquid temperature of 40 ° C. After impact-mixing at a discharge pressure of 16 MPa by a machine, discharge at a discharge rate of 800 g / sec into a mold kept at 40 ° C. and let go for 10 minutes. By placing, a foamed polyurethane block having a thickness of 10.0 mm (density: 0.78 g / cm ³ , average cell diameter: 35 μm) was produced. Thereafter, the foamed polyurethane block was sliced with a slicer to a thickness of 2 mm.

Next, the foamed polyurethane sheet was immersed in methyl methacrylate to which 0.1 part by weight of azobisisobutyronitrile was added for 45 minutes. Next, the foamed polyurethane sheet impregnated with methyl methacrylate was sandwiched between two glass plates via a vinyl chloride gasket, and polymerized and cured by heating at 70 ° C. for 10 hours and at 120 ° C. for 3 hours. After releasing from between the glass plates, vacuum drying was performed at 50 ° C. A polishing layer was prepared by grinding both surfaces of the hard foam sheet thus obtained to a thickness of 2.00 mm. The obtained polishing layer had a micro rubber A hardness of 96, a density of 0.79 g / cm ³ , and an average cell diameter of 42 μm.

Next, a urethane hot-melt adhesive is applied to one side of the polishing layer with a roll coater to a thickness of about 80 μm, and a polyurethane rubber sheet (thickness 0.3 mm, micro rubber A hardness 82) is quickly applied as a cushion layer thereon. Then, it was pressed with a roll press and bonded to the polishing layer. Double-sided adhesive tape “442JS” (manufactured by Sumitomo 3M Co., Ltd. (trade name)) is laminated with a laminator as a back surface tape to be bonded to the polishing machine on the cushion layer side surface of the laminate of the polishing layer and the cushion layer, A polishing pad laminate was obtained.
Grooves having a groove width of 1 mm, a groove pitch of 15 mm, and a groove depth of 1.5 mm were formed in a lattice shape on the entire surface of the polishing layer of the laminate thus produced, and processed into a circular shape with a diameter of 508 mm to obtain a polishing pad.

f. Deformation evaluation The polishing pad package was sandwiched between two paper cardboard plates (length of about 540 mm on one side, thickness of about 5 mm), and the vicinity of the center of each side of the cardboard plate was fixed with tape. Next, the polishing pad package sandwiched between the two corrugated boards was leaned against the wall and placed vertically for 30 days.

  The polishing pad was taken out from the package of the polishing pad sandwiched between the two corrugated cardboard plates after standing for 30 days and placed on a horizontal table, and the degree of floating of the pad end surface from the table was measured to obtain the amount of deformation. When a plurality of polishing pads exist in one polishing pad package, the value of the polishing pad having the largest lift at the end was adopted. The amount of deformation was 15 mm or less, and 5 mm or less was particularly excellent. When the amount of deformation exceeded 15 mm, it was rejected.

g. Yellowing evaluation Using an integrating sphere spectrocolorimeter “SP60” (manufactured by X-Rite), after measuring the surface of the polishing pad before packing with a bag-shaped packing material, It was left on a horizontal table for 180 days. After standing for 180 days, the polishing pad was taken out from the package of the polishing pad, and the surface of the polishing pad was measured with an integrating sphere spectrocolorimeter in the same manner as before standing, and the color difference Δb ^* was determined from the measured value.

Color difference Δb ^* = (b ^* after standing for 180 days) − (b ^* before packing).

When a plurality of polishing pads exist in one polishing pad package, the value of the polishing pad having the largest color difference Δb ^* was adopted. A color difference Δb ^* of 3 or less was accepted and 1 or less was particularly excellent. If the color difference Δb ^* exceeds 3, the test was rejected.

[Example 1]
The prepared two polishing pads were oriented so that the polishing surfaces face each other, and then overlapped with a misalignment angle formed by the grooves between the opposing polishing pads being set to 20 °, and then a polyethylene bag (thickness 100 μm, wavelength 550 nm). And the inner air was vacuumed and removed, and the opening was fused and packed with a heat sealer to prepare a polishing pad package. A schematic cross-sectional view of the polishing pad package of this example is shown in FIG.

[Example 2]
After making the prepared 6 polishing pads in such a way that the polishing surfaces face each other in pairs, the gap between the polishing pads facing each other was overlapped with an angle of 45 °, and then a polyethylene bag ( 2 pieces into a set of 100 μm in thickness and light transmittance of 75% in wavelength of 550 nm). While removing air by evacuating the inside, the opening is fused and packed with a heat sealer. Produced. Next, 3 sets of this polishing pad package are put in a polyethylene bag (thickness 100 μm, light transmittance 75% of wavelength 550 nm), and the opening is opened with a heat sealer while removing the air inside by vacuuming. Fused and secondary packed. A schematic cross-sectional view of the polishing pad package of this example is shown in FIG.

[Example 3]
The prepared three polishing pads were aligned so that the polishing surfaces face each other in pairs, and then overlapped with the angle of deviation formed by the grooves between the opposing polishing pads being 15 °. Furthermore, the other polishing pad is placed on the two polishing pads previously superposed with the polishing surface on the bottom so that the misalignment angle with the groove of the polishing pad superposed on the upper side is 15 °. Overlaid. Put these three polishing pads into a polyethylene bag (thickness 100μm, light transmittance 75% of wavelength 550nm), vacuum the inside air and remove it, fuse the opening with a heat sealer and pack it Then, a polishing pad package was prepared. A schematic cross-sectional view of the polishing pad package of this example is shown in FIG.

[Example 4]
The prepared two polishing pads were oriented so that the polishing surfaces face each other, and then overlapped with a misalignment angle formed by grooves between the opposing polishing pads set to 8 °, and then a polyethylene bag (thickness 100 μm, wavelength 550 nm). And the inner air was vacuumed and removed, and the opening was fused and packed with a heat sealer to prepare a polishing pad package. A schematic cross-sectional view of the polishing pad package of this example is shown in FIG.

[Example 5]
After aligning the two polishing pads so that the polishing surfaces face each other, and aligning the groove positions between the polishing pads (shift angle 0 °), they are overlapped, and then a polyethylene bag (thickness 100 μm, wavelength) 550 nm light transmittance was 75%), and the air inside was vacuumed and removed, and the opening was fused and packed with a heat sealer to prepare a polishing pad package. A schematic cross-sectional view of the polishing pad package of this example is shown in FIG.

[Comparative Example 1]
Put only one polishing pad into a polyethylene bag (thickness 100 μm, light transmittance of wavelength 550 nm 75%) and melt the opening with a heat sealer while removing the internal air by vacuum. The product was packed to prepare a polishing pad package. A schematic cross-sectional view of the polishing pad package of this comparative example is shown in FIG.

[Comparative Example 2]
After making the orientation so that the back surfaces of the two polishing pads produced face each other, the groove positions of the polishing pads facing the back surfaces are aligned (shift angle 0 °) and overlapped, and then a polyethylene bag (thickness) 100 μm and light transmittance of a wavelength of 550 nm (75%), and the inside air was vacuumed and removed, and the opening was fused and packed with a heat sealer to prepare a polishing pad package.

[Comparative Example 3]
After making the 6 polishing pads prepared so that the polishing surfaces face the same direction, the grooves of each polishing pad were aligned (shift angle 0 °) and then overlapped, and then a polyethylene bag (thickness 100 μm, wavelength) 550 nm light transmittance (75%), and without removing the air inside, the opening was fused and packed with a heat sealer to prepare a polishing pad package.

  From Table 1, it can be seen that the polishing pad package of the present invention is less susceptible to yellowing during storage and the deformation amount is small.

DESCRIPTION OF SYMBOLS 1 Polishing layer 2 Cushion layer 3 Back surface tape 4 Polishing surface 5 Packing material 6 Polishing pad packing material 7 Polishing pad primary packing material 9 Secondary packing material 10 Polishing pad A
11 Groove 20 of polishing pad A Polishing pad B
21 Groove of polishing pad B

Claims (7)

A polishing pad package comprising a plurality of polishing pads packed with a packing material, wherein the polishing pads are stacked and packed so that the polishing surfaces of the two polishing pads are in contact with each other as much as possible. Pad packing. 2. The polishing pad package according to claim 1, wherein the two polishing pads are overlapped so that the positions of grooves formed on the respective polishing surfaces do not overlap each other. The polishing pad package according to claim 2, wherein the groove formed on the polishing surface of the polishing pad includes a groove having a linear shape. The polishing pad package according to claim 3, wherein the polishing pads are overlapped with each other with a groove shift angle of 10 ° or more. The polishing pad package according to any one of claims 1 to 4, wherein the package includes two sheets. The polishing pad package according to any one of claims 1 to 5, wherein the air inside the packing material is evacuated. A method of packing a plurality of polishing pads, wherein the polishing pads are stacked and packed so that the polishing surfaces of the two polishing pads are in contact with each other as much as possible.