Sub-pad for polishing pad, polishing pad including same, and method for manufacturing sub-pad for polishing pad

Patent metadata

Field	Value
Publication number	US-2025249547-A1
Application number	US-202318856158-A
Country	US
Kind code	A1
Filing date	Apr 13, 2023
Priority date	Apr 14, 2022
Publication date	Aug 7, 2025
Grant date	—

Abstract

A sub-pad for a polishing pad is disclosed. The sub-pad is stacked under a top pad that is brought into contact with a wafer to perform polishing, and includes a nanofiber nonwoven fabric pad. The nanofiber nonwoven fabric pad has a nanofiber density of an outer circumferential part that is formed to be 1.2 to 5 times higher than the nanofiber density of other portions inside the outer circumferential part. A polishing pad including the sub-pad and a method for manufacturing the sub-pad for the polishing pad are disclosed.

First claim

1 . A sub-pad for a polishing pad, the sub-pad being stacked under a top pad that is brought into contact with a wafer to perform polishing, and including a nanofiber nonwoven fabric pad, wherein the nanofiber nonwoven fabric pad has a nanofiber density of an outer circumferential part that is formed to be 1.2 to 5 times higher than the nanofiber density of other portions inside the outer circumferential part.

2 . The sub-pad for the polishing pad according to claim 1 ,
wherein the nanofiber density of the outer circumferential part is 1.5 to 5 times higher than the nanofiber density of other portions inside the outer circumferential part.

3 . The sub-pad for the polishing pad according to claim 1 ,
wherein the nanofiber nonwoven fabric pad includes a hydrophobic polymer.

4 . The sub-pad for the polishing pad according to claim 3 ,
wherein the hydrophobic polymer is at least one selected from a group consisting of polystyrene and Teflon (PTFE, Polytetrafluoroethylene).

5 . The sub-pad for the polishing pad according to claim 1 ,
wherein the outer circumferential part of the sub-pad functions to prevent penetration of a polishing slurry due to a low porosity.

6 . A polishing pad, comprising:
a top pad that is brought into contact with a wafer to perform polishing; and the sub-pad of claim 1 stacked under the top pad.

7 . The polishing pad according to claim 6 ,
wherein a cross section of the outer circumferential part of the sub-pad is exposed to the outer circumferential surface of the polishing pad.

8 . A method for manufacturing the sub-pad for the polishing pad of claim 1 , the method comprising the steps of:
a) electrospinning a polymer solution; b) recovering the nanofiber nonwoven fabric formed by the electrospinning; and c) thermally compressing the nanofiber nonwoven fabric, wherein the collector during electrospinning of the step a) includes a circular electrode corresponding to the outer circumferential part of the sub-pad.

9 . The method for manufacturing the sub-pad for the polishing pad according to claim 8 ,
wherein the collector includes an electrospinning-induced film, and the circular electrode is formed on the surface of the electrospinning-induced film.

10 . The method for manufacturing the sub-pad for the polishing pad according to claim 9 ,
wherein the circular electrode is printed on the surface of the electrospinning-induced film.

11 . The method for manufacturing the sub-pad for the polishing pad according to claim 9 ,
wherein two or more nanofiber nonwoven fabrics recovered in the step b) are stacked such that high density portions of the nanofiber formed on the top of a circular electrode overlap each other, and the stacked nanofiber nonwoven fabrics are thermally compressed in the step c).

12 . The method for manufacturing the sub-pad for the polishing pad according to claim 9 ,
wherein a plurality of circular electrodes are formed on the surface of electrospinning-induced films, and the plurality of circular electrodes are electrically connected by a conductive material, the electrospinning-induced film collects nanofibers spun while moving horizontally, or the electrospinning-induced film collects nanofibers spun while rotating in the state of being wound around a circular drum.

Assignees

• Kpx Chemical Co Ltd
• Korea Advanced Inst Sci & Tech

Inventors

• Min Byung Ju
• Kim Seung Geun
• Kang Min Woo
• Oh Nam Gue
• Kim San Ha
• Jeong Ji Hun
• Eom Youn Sick

Classifications

• B24D11/001

  Manufacture of flexible abrasive materials · CPC title

• B24B37/22 Primary

  characterised by a multi-layered structure · CPC title

• B24B37/24

  characterised by the composition or properties of the pad materials · CPC title

• B24D11/00

  Constructional features of flexible abrasive materials; Special features in the manufacture of such materials · CPC title