Mechanical polishing pad with CMP (chemical mechanical polishing) composite groove and preparation method of mechanical polishing pad

Abstract

The invention discloses a mechanical polishing pad with a CMP composite groove and a preparation method of the mechanical polishing pad, and belongs to the technical field of polishing pads. The mechanical polishing pad comprises a polishing layer, a bonding layer and a substrate layer, and the polishing layer is bonded to the surface of the substrate layer through the bonding layer; the bonding layer is prepared from the following raw materials in parts by mass: 47 to 50 parts of EVA resin, 35 to 36 parts of tackifier, 8 to 12 parts of paraffin, 3 to 7 parts of filler and 0.5 to 2 parts of antioxidant. The mechanical polishing pad solves the problem that when an existing mechanical polishing pad is used, a groove of the mechanical polishing pad cannot well convey polishing liquid, the mechanical polishing pad cannot be well supported, and the mechanical polishing effect is poor. The polishing liquid conveying performance of the mechanical polishing pad can be improved, the mechanical polishing pad is prevented from deforming during polishing, it can be guaranteed that polishing pressure is evenly transmitted, the size stability and the compression permanent deformation resistance of the mechanical polishing pad can be improved, and the mechanical polishing effect can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polishing pads, in particular to a mechanical polishing pad with CMP composite grooves and a preparation method thereof. Background Art

[0002] Chemical mechanical polishing is a micro-nano processing technology that combines mechanical grinding and chemical oxidation to remove surface material of the workpiece being processed. This technology can make the surface of the workpiece being processed ultra-flat and ultra-smooth, and is mainly used in the fields of IC and MEMS manufacturing.

[0003] When the existing mechanical polishing pad is in use, its grooves cannot properly transport the polishing liquid and cannot properly support the mechanical polishing pad, resulting in poor mechanical polishing effect. Summary of the Invention

[0004] The purpose of the present invention is to provide a mechanical polishing pad with CMP composite grooves and a preparation method thereof, which can improve the polishing liquid delivery performance of the mechanical polishing pad, prevent the mechanical polishing pad from deforming during polishing, ensure uniform transmission of polishing pressure, improve the dimensional stability and resistance to permanent compression deformation of the mechanical polishing pad, effectively improve the mechanical polishing effect, and solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A mechanical polishing pad with CMP composite grooves comprises a polishing layer, an adhesive layer and a base layer. The polishing layer is bonded to the surface of the base layer via the adhesive layer. The adhesive layer comprises the following raw materials in parts by mass: 47-50 parts of EVA resin, 35-36 parts of tackifier, 8-12 parts of paraffin wax, 3-7 parts of filler and 0.5-2 parts of antioxidant.

[0007] Preferably, the surface of the polishing layer is provided with circular grooves, and the number of the circular grooves is three, and the three circular grooves expand sequentially from the inside to the outside.

[0008] Preferably, the surface of the polishing layer is provided with strip grooves, and the strip grooves are distributed in a radial shape.

[0009] Preferably, the circular grooves and the strip grooves are connected, wherein adjacent circular grooves are connected via the strip grooves.

[0010] Preferably, the polishing layer comprises the following raw materials in parts by mass: 50-70 parts of submicron cerium oxide, 2-5 parts of zirconium oxide, 5-10 parts of chromium oxide, 10-15 parts of rare earth, 5-10 parts of silicon dioxide and the balance of cobalt.

[0011] Preferably, the base layer includes a supporting bottom layer and a supporting surface layer, the upper surface of the supporting bottom layer is provided with a supporting surface layer, and the supporting surface layer is connected to the polishing layer through an adhesive layer, wherein the supporting bottom layer and the supporting surface layer are both made of thermoplastic polyurethane material.

[0012] Preferably, the base layer also includes a support member, a connecting member, a support column and a positioning block. The support member is connected to the periphery of the positioning block through the connecting member. A support column is provided on the support member, and the two ends of the support column respectively contact the supporting bottom layer and the supporting surface layer.

[0013] Preferably, the support members are distributed at equal intervals on the periphery of the positioning block, and adjacent support members are connected by connecting members.

[0014] According to another aspect of the present invention, there is also provided a method for preparing a mechanical polishing pad having CMP composite grooves as described above, comprising the following steps:

[0015] Preparation of polishing layer:

[0016] Submicron cerium oxide, zirconium oxide, chromium oxide, rare earth, silicon dioxide and cobalt are added into a mixing grinder in proportion and fully mixed and ground, and then molded to form a polishing layer;

[0017] The polishing layer is precisely processed using a CNC engraving machine, and circular grooves and strip grooves that are interconnected are processed on the surface of the polishing layer;

[0018] Prepare the bonding layer:

[0019] Adding EVA resin, tackifier, paraffin, filler and antioxidant into a disperser in proportion, and using the disperser to disperse and emulsify the EVA resin, tackifier, paraffin, filler and antioxidant, wherein the dispersion speed is 1200-2400 rpm and the dispersion time is 20-40 min to form an EVA hot melt adhesive;

[0020] Prepare the base layer:

[0021] The support bottom layer and the support surface layer are prepared using thermoplastic polyurethane material, a groove is opened on the support bottom layer, and the support member is processed on the periphery of the positioning block through a connecting member, and a support column is processed on the support member;

[0022] Processing the processed support parts, connectors, support columns and positioning blocks on the inner sides of the support bottom layer and the support surface layer to form a base layer;

[0023] Prepare mechanical polishing pad:

[0024] EVA hot melt adhesive is coated on the base layer, and a polishing layer is arranged on the EVA hot melt adhesive. After lamination and curing, a mechanical polishing pad is formed.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides composite grooves consisting of circular grooves and strip grooves on the surface of the polishing layer, wherein the circular grooves and the strip grooves are interconnected, which can better transport the polishing liquid and improve the polishing liquid transport performance of the mechanical polishing pad. By providing a support assembly consisting of support members, connecting members, support columns and positioning blocks on the inner side of the support bottom layer and the support surface layer, the support assembly can effectively support the base layer, prevent the mechanical polishing pad from deforming during polishing, ensure uniform transmission of polishing pressure, improve the dimensional stability and resistance to permanent compression deformation of the mechanical polishing pad, and effectively improve the mechanical polishing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of a mechanical polishing pad with CMP composite grooves according to the present invention;

[0028] Figure 2 is a top view schematic diagram of the polishing layer of the present invention;

[0029] Figure 3 Schematic diagram of the structure of the base layer of the present invention;

[0030] Figure 4 It is a top view schematic diagram of the supporting bottom layer of the present invention;

[0031] Figure 5 It is a structural schematic diagram of the supporting bottom layer of the present invention;

[0032] Figure 6 This is a top view of a support member disposed in a support bottom layer according to embodiment 1 of the present invention;

[0033] Figure 7 This is a top view of a support member disposed in a support bottom layer according to a second embodiment of the present invention;

[0034] Figure 8 This is a top view of a support member disposed in a support bottom layer according to a third embodiment of the present invention.

[0035] In the figure: 1, polishing layer; 11, circular groove; 12, strip groove; 2, adhesive layer; 3, base layer; 31, supporting bottom layer; 32, supporting surface layer; 33, supporting member; 34, connecting member; 35, supporting column; 36, positioning block. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] In order to solve the problem that the grooves of the existing mechanical polishing pad cannot properly transport the polishing liquid and cannot properly support the mechanical polishing pad during use, resulting in poor mechanical polishing effect, please refer to Figures 1-8 , this embodiment provides the following technical solutions:

[0038] Example 1

[0039] A mechanical polishing pad with CMP composite grooves includes a polishing layer 1, an adhesive layer 2 and a base layer 3. The polishing layer 1 is bonded to the surface of the base layer 3 through the adhesive layer 2. The adhesive layer 2 includes the following raw materials in parts by weight: 47-50 parts of EVA resin, 35-36 parts of tackifier, 8-12 parts of paraffin wax, 3-7 parts of filler and 0.5-2 parts of antioxidant.

[0040] In this embodiment, the surface of the polishing layer 1 is provided with three circular grooves 11 , and the three circular grooves 11 are expanded sequentially from the inside to the outside.

[0041] In this embodiment, strip grooves 12 are provided on the surface of the polishing layer 1 , and the strip grooves 12 are distributed in a radial shape.

[0042] In this embodiment, the circular grooves 11 and the strip grooves 12 are connected, wherein adjacent circular grooves 11 are connected via the strip grooves 12 .

[0043] Specifically, by providing a composite groove consisting of a circular groove 11 and a strip groove 12 on the surface of the polishing layer 1, wherein the circular groove 11 and the strip groove 12 are interconnected, the polishing liquid can be better transported and the mechanical polishing effect can be effectively improved.

[0044] In this embodiment, the polishing layer 1 includes the following raw materials in parts by mass: 50-70 parts of submicron cerium oxide, 2-5 parts of zirconium oxide, 5-10 parts of chromium oxide, 10-15 parts of rare earth, 5-10 parts of silicon dioxide and the balance of cobalt.

[0045] In this embodiment, the base layer 3 includes a supporting bottom layer 31 and a supporting surface layer 32. The upper surface of the supporting bottom layer 31 is provided with the supporting surface layer 32. The supporting surface layer 32 is connected to the polishing layer 1 through the adhesive layer 2. The supporting bottom layer 31 and the supporting surface layer 32 are both made of thermoplastic polyurethane material, which has good wear resistance.

[0046] In this embodiment, the base layer 3 also includes a support member 33, a connecting member 34, a support column 35 and a positioning block 36. The support member 33 is connected to the periphery of the positioning block 36 through the connecting member 34. A support column 35 is provided on the support member 33, and the two ends of the support column 35 respectively contact the supporting bottom layer 31 and the supporting surface layer 32.

[0047] In this embodiment, the support members 33 are distributed at equal intervals around the periphery of the positioning block 36 , and adjacent support members 33 are connected by connecting members 34 .

[0048] In this embodiment, there are four support members 33 , which are connected by a connecting member 34 , and each of the four support members 33 is provided with a support column 35 .

[0049] Specifically, by arranging a support assembly consisting of a support member 33, a connecting member 34, a support column 35 and a positioning block 36 on the inner side of the support bottom layer 31 and the support surface layer 32, the support assembly can effectively support the base layer 3, prevent the mechanical polishing pad from deforming during polishing, ensure uniform transmission of polishing pressure, and improve the dimensional stability and resistance to permanent compression deformation of the mechanical polishing pad.

[0050] In order to better illustrate the preparation process of a mechanical polishing pad having CMP composite grooves, this embodiment now provides a method for preparing a mechanical polishing pad having CMP composite grooves as described above, comprising the following steps:

[0051] Preparation of polishing layer 1:

[0052] Submicron cerium oxide, zirconium oxide, chromium oxide, rare earth, silicon dioxide and cobalt are added into a mixing grinder in proportion, mixed and ground thoroughly, and then molded to form a polishing layer 1;

[0053] The polishing layer 1 is precisely machined using a CNC engraving machine, and circular grooves 11 and strip grooves 12 that are interconnected are machined on the surface of the polishing layer 1;

[0054] Preparation of adhesive layer 2:

[0055] Adding EVA resin, tackifier, paraffin, filler and antioxidant into a disperser in proportion, and using the disperser to disperse and emulsify the EVA resin, tackifier, paraffin, filler and antioxidant, wherein the dispersion speed is 1200-2400 rpm and the dispersion time is 20-40 min to form an EVA hot melt adhesive;

[0056] Preparation of base layer 3:

[0057] The support bottom layer 31 and the support surface layer 32 are made of thermoplastic polyurethane material, and a groove is opened on the support bottom layer 31. The support member 33 is processed on the periphery of the positioning block 36 through the connecting member 34, and the support column 35 is processed on the support member 33.

[0058] The processed support members 33, connectors 34, support columns 35 and positioning blocks 36 are processed on the inner sides of the support bottom layer 31 and the support surface layer 32 to form the base layer 3;

[0059] Prepare mechanical polishing pad:

[0060] EVA hot melt adhesive is coated on the base layer 3, and a polishing layer 1 is provided on the EVA hot melt adhesive. After lamination and curing, a mechanical polishing pad is formed.

[0061] Example 2

[0062] The difference from the first embodiment is that the number of support members 33 , connecting members 34 and support columns 35 is different. The number of support members 33 in this embodiment is two, the two support members 33 are connected by a connecting member 34 , and support columns 35 are provided on both support members 33 .

[0063] The mechanical polishing pad is prepared by the same preparation method as in Example 1. The difference from Example 1 is that the number of support members 33, connecting members 34 and support columns 35 in Example 2 is reduced.

[0064] Example 3

[0065] The difference from the first embodiment is that the number of support members 33 , connecting members 34 and support columns 35 is different. The number of support members 33 in this embodiment is six, and the six support members 33 are connected by connecting members 34 , and support columns 35 are provided on all six support members 33 .

[0066] The mechanical polishing pad is prepared by the same preparation method as in Example 1. The difference from Example 1 is that the number of support members 33, connecting members 34 and support columns 35 in Example 3 is increased.

[0067] Comparative Example

[0068] A mechanical polishing pad with CMP composite grooves comprises a polishing layer 1, an adhesive layer 2 and a base layer 3. The polishing layer 1 is bonded to the surface of the base layer 3 through the adhesive layer 2. The surface of the polishing layer 1 is provided with circular grooves 11.

[0069] In this embodiment, the polishing layer 1 includes the following raw materials in parts by mass: 50-70 parts of submicron cerium oxide, 2-5 parts of zirconium oxide, 5-10 parts of chromium oxide, 10-15 parts of rare earth, 5-10 parts of silicon dioxide and the balance of cobalt.

[0070] The mechanical polishing pad is prepared by the same preparation method as in Example 1, and the preparation steps of the strip groove 12, the supporting bottom layer 31, the supporting surface layer 32, the supporting member 33, the connecting member 34, the supporting column 35 and the positioning block 36 are correspondingly eliminated.

[0071] The mechanical polishing pads prepared in Examples 1-3 and the comparative example were subjected to performance tests, wherein the specific test process is as follows:

[0072] 1) Polishing liquid delivery performance test:

[0073] According to the visual flow test method, a mechanical polishing pad with an actual groove structure is simulated on a transparent acrylic plate or glass plate. A transparent or dyed simulated polishing liquid is used. Water or glycerol solution is used to simulate viscosity. The flow state of the liquid in the groove is recorded by a high-speed camera. The speed of liquid diffusion in the groove network is observed to see whether the liquid can evenly cover the entire area. After the liquid supply is stopped, the speed and thoroughness of the liquid in the groove when it is rotated by centrifugal force or discharged by gravity are measured to test the polishing liquid delivery performance.

[0074] 2) Anti-deformation performance test:

[0075] According to the static compression set test method, a mechanical polishing pad sample of specified size is placed between parallel plates, constant pressure is applied and maintained for a specified time, and after the pressure is removed, the residual thickness deformation of the sample is measured after a specified recovery time. The compression set rate (%) is calculated as [(initial thickness - thickness after recovery) / initial thickness] * 100%. The lower the value, the stronger the material's resistance to permanent deformation and the better the dimensional stability.

[0076] Among them, the performance test results of the mechanical polishing pad are shown in Table 1:

[0077] Table 1: Performance test results of mechanical polishing pads

[0078]

[0079]

[0080] As can be seen from the above table, the mechanical polishing pads prepared in Examples 1 to 3 all have good polishing liquid delivery performance, anti-deformation performance and dimensional stability.

[0081] Among them, compared with Example 1, Example 2 has basically the same polishing liquid delivery performance, but the anti-deformation performance and dimensional stability performance are reduced, indicating that the reduction in the number of support members 33, connecting members 34 and support columns 35 reduces the anti-deformation performance and dimensional stability performance of the mechanical polishing pad;

[0082] Among them, compared with Example 1, Example 3 has basically the same polishing liquid delivery performance, but the anti-deformation performance and dimensional stability performance are improved, indicating that the increase in the number of support members 33, connecting members 34 and support columns 35 improves the anti-deformation performance and dimensional stability performance of the mechanical polishing pad;

[0083] Among them, compared with Example 1, the polishing liquid delivery performance of the comparative example is reduced, which shows that providing interconnected circular grooves 11 and strip grooves 12 on the surface of the polishing layer 1 can improve the polishing liquid delivery performance of the mechanical polishing pad.

[0084] In summary, the present invention sets a composite groove consisting of a circular groove 11 and a strip groove 12 on the surface of the polishing layer 1, wherein the circular groove 11 and the strip groove 12 are interconnected, which can better transport the polishing liquid and improve the polishing liquid transport performance of the mechanical polishing pad. By setting a support assembly consisting of a support member 33, a connecting member 34, a support column 35 and a positioning block 36 on the inner side of the support bottom layer 31 and the support surface layer 32, the support assembly can effectively support the base layer 3, prevent the mechanical polishing pad from deforming during polishing, ensure uniform transmission of polishing pressure, improve the dimensional stability and resistance to permanent compression deformation of the mechanical polishing pad, and effectively improve the mechanical polishing effect.

[0085] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0086] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A mechanical polishing pad with a CMP composite groove, characterized in that: The invention comprises a polishing layer (1), an adhesive layer (2) and a base layer (3), wherein the polishing layer (1) is bonded to the surface of the base layer (3) via the adhesive layer (2), and the adhesive layer (2) comprises the following raw materials in parts by mass: 47-50 parts of EVA resin, 35-36 parts of tackifier, 8-12 parts of paraffin wax, 3-7 parts of filler and 0.5-2 parts of antioxidant.

2. A mechanical polishing pad with CMP composite grooves according to claim 1, characterized in that: The surface of the polishing layer (1) is provided with circular grooves (11), the number of the circular grooves (11) is three, and the three circular grooves (11) expand sequentially from the inside to the outside.

3. The mechanical polishing pad with CMP composite grooves according to claim 2, characterized in that: The surface of the polishing layer (1) is provided with strip-shaped grooves (12), and the strip-shaped grooves (12) are distributed in a radial shape.

4. The mechanical polishing pad with CMP composite grooves according to claim 3, wherein: The circular grooves (11) and the strip grooves (12) are connected, wherein adjacent circular grooves (11) are connected via the strip grooves (12).

5. The mechanical polishing pad with CMP composite grooves according to claim 4, characterized in that: The polishing layer (1) comprises the following raw materials in parts by mass: 50-70 parts of submicron cerium oxide, 2-5 parts of zirconium oxide, 5-10 parts of chromium oxide, 10-15 parts of rare earth, 5-10 parts of silicon dioxide and the balance of cobalt.

6. The mechanical polishing pad with CMP composite grooves according to claim 5, characterized in that: The base layer (3) comprises a supporting bottom layer (31) and a supporting surface layer (32); the supporting surface layer (32) is provided on the upper surface of the supporting bottom layer (31); the supporting surface layer (32) is connected to the polishing layer (1) via an adhesive layer (2); wherein the supporting bottom layer (31) and the supporting surface layer (32) are both made of thermoplastic polyurethane material.

7. The mechanical polishing pad with CMP composite grooves according to claim 6, characterized in that: The base layer (3) further comprises a support member (33), a connecting member (34), a support column (35) and a positioning block (36); the support member (33) is connected to the periphery of the positioning block (36) via the connecting member (34); a support column (35) is provided on the support member (33); and two ends of the support column (35) respectively contact the supporting bottom layer (31) and the supporting surface layer (32).

8. The mechanical polishing pad with CMP composite grooves according to claim 7, characterized in that: The support members (33) are distributed at equal intervals on the periphery of the positioning block (36), and adjacent support members (33) are connected via connecting members (34).

9. A method for preparing a mechanical polishing pad with CMP composite grooves according to claim 8, characterized in that: The steps include: Preparation of polishing layer (1): Submicron cerium oxide, zirconium oxide, chromium oxide, rare earth, silicon dioxide and cobalt are added into a mixing grinder in proportion, mixed and ground thoroughly, and then molded to form a polishing layer (1); The polishing layer (1) is precisely machined using a numerically controlled engraving machine, and circular grooves (11) and strip grooves (12) that are interconnected are machined on the surface of the polishing layer (1); Preparation of adhesive layer (2): Adding EVA resin, tackifier, paraffin, filler and antioxidant into a disperser in proportion, and using the disperser to disperse and emulsify the EVA resin, tackifier, paraffin, filler and antioxidant, wherein the dispersion speed is 1200-2400 rpm and the dispersion time is 20-40 min to form an EVA hot melt adhesive; Preparation of base layer (3): A support bottom layer (31) and a support surface layer (32) are prepared using thermoplastic polyurethane material, a groove is provided on the support bottom layer (31), a support member (33) is processed on the periphery of a positioning block (36) through a connecting member (34), and a support column (35) is processed on the support member (33); Processing the processed support members (33), connecting members (34), support columns (35) and positioning blocks (36) on the inner sides of the support bottom layer (31) and the support surface layer (32) to form a base layer (3); Prepare mechanical polishing pad: An EVA hot melt adhesive is coated on a base layer (3), and a polishing layer (1) is arranged on the EVA hot melt adhesive. After lamination and curing, a mechanical polishing pad is formed.

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