Study on Degradation of Ceria-based Slurry in Glass polishing

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04222
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 18020:Manufacturing and production engineering-related
• Research Institution: Japan Fine Ceramics Center
• Principal Investigator: KAWAHARA Koichi 一般財団法人ファインセラミックスセンター, その他部局等, 主任研究員 (00302175)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: セリア系砥粒 / CMP / スラリー循環式研磨 / 寿命

Outline of Final Research Achievements

Long-term glass polishing tests using the ceria-based slurry were performed to clarify the important factor affecting to the degradation of ceria-based slurry. The slurry with La-doped ceria showed the typical degradation profiles classified into two degradation regions; the region where degradation was not severe (Region I) and the region where the removal rate rapidly decreased with polishing time (Region II). Y-doped ceria slurry was found to show almost the same degradation behavior. These results indicated the degradation behavior of the ceria-base slurry was independent of the species of doped trivalent cations. The evaluations of the degradation behavior under different polishing conditions revealed that the important factor was the ratio of the solvent volume and the total amount of removed glass. The glass fragments introduced into the slurry would be the cause of abrasive aggregation then lead to the severe degradation.

Free Research Field

砥粒合成

Academic Significance and Societal Importance of the Research Achievements

本研究は、市販セリア系砥粒を模擬した球状砥粒を合成し、砥粒スラリー劣化挙動に影響を与える因子を抽出することを目的に行われた。本研究では、セリア系砥粒スラリーを用いた研磨では、劣化挙動はセリアに添加した3価のカチオン種や、研磨圧力などの研磨条件にはほとんど依存せず、砥粒スラリーの溶媒の体積とスラリー中に混入したガラス量に依存すること、劣化原因がスラリー中の砥粒の凝集であることが明らかとなった。スラリー循環式研磨における砥粒スラリーの寿命は、ガラス精密研磨の現場ではコストに直結する重要な因子でもあることから、本研究で得られた結果は、砥粒スラリーの寿命延長や再生の分野に対して指針を示すものである。