ABRASIVE PAD AND METHOD FOR MANUFACTURING THE SAME

PROBLEM TO BE SOLVED: To provide an abrasive pad capable of remarkably reducing occurrence of defects of a polished object, an abrasive pad excellent in polishing stability, and a method for manufacturing the abrasive pads.SOLUTION: According to one embodiment, an urethane foam sheet showing negative thermal expansion when loading pressure more than 2.5 psi (17 kPa) at temperature of 40-50°C is used for an abrasive pad. The urethane foam sheet preferably shows positive thermal expansion when loading pressure less than 1.0 psi (6.9 kPa) at temperature of 40-50°C. According to another embodiment, an urethane foam sheet having a strain constant of 45-150 μm/psi when loading pressure of 1.0-2.5 psi is used for an abrasive pad.SELECTED DRAWING: Figure 1 【課題】被研磨物のディフェクトの発生を著しく低減できる研磨パッド、研磨安定性に優れた研磨パッド及びそれらの製造方法を提供する。【解決手段】一態様によれば、温度４０〜５０℃で２．５ｐｓｉ（１７ｋＰａ）を超える圧力を負荷したとき、負の熱膨張を示す発泡ウレタンシートを研磨パッドに用いる。前記発泡ウレタンシートは、温度４０〜５０℃で１．０ｐｓｉ（６．９ｋＰａ）未満の圧力を負荷したとき、正の熱膨張を示すのが好ましい。また、別の態様によれば、１．０〜２．５ｐｓｉの圧力を負荷したとき、４５〜１５０μｍ/ｐｓｉの歪定数を有する発泡ウレタンシートを研磨パッドに用いる。【選択図】図１