201107077 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種板狀體之研磨方法，尤其係關於一種 藉由研磨裝置研磨液晶顯示器等中所使用之FpD(Flat Panel Display ’平板顯示器）用之玻璃基板的板狀體之研磨 方法。 【先前技術】 液晶顯示器等中所使用之FPD用之玻璃基板係利用被稱 為浮式法之玻璃製法將熔融玻璃成形為板狀，並藉由專利 文獻1等中所揭示之連續式研磨裝置研磨去除其表面之微 小的凹凸或起伏，藉此，製成滿足液晶顯示器用玻璃基板 所要求之平坦度的厚度約為〇·4〜ι·ι mm的薄板。 於此種連續式研磨裝置中，如專利文獻2中所記載般， 一般係藉由自轉及公轉之研磨墊（研磨具）研磨玻璃基板。 於先前之連續式研磨裝置中，將玻璃基板之與其研磨對 象面為相反側之面吸附保持在接著於平台的吸附片材上， 一面藉由搬送平台之搬送裝置連續地搬送玻璃基板，一面 藉由設置於該搬送路徑之上方之複數台研磨機的研磨墊依 序對研磨對象面進行研磨。研磨墊係藉由自轉/公轉機構 以特疋之旋轉中心為中心而旋轉，並且一面以特定之公轉 中心為中心而公轉，-面研磨玻璃基板。X，於使用矩形 之研磨塾之情形時’僅進行公轉運動。作為使用矩形之研 磨墊之連續式研磨褒置，存在有僅包含矩形之研磨塾之連 續式研磨裝置、或組合矩形之研磨塾與進行自轉公轉之圓 148796.doc 201107077 形之研磨墊而成的連續式研磨裝置。 [先前技術文獻] [專利文獻] [專利文獻1]日本專利特開2007-190657號公報 [專利文獻2]曰本專利特開2001-29365 6號公報 【發明内容】 [發明所欲解決之問題] 先前之研磨裝置存在如下問題：隨著研磨時間之流逝， 玻璃基板之研磨率將降低，若研磨率低於特定之臨界值， 則需要對其研磨墊進行整形或修整，因此無法提昇玻璃基 板之生產效率。又，先前之研磨裝置亦存在如下問題：即 便於無需對研磨具進行整形或修整之情形時，研磨率亦將 隨著研磨時間之流逝而降低，因此無法使研磨率大致固定 而連續地研磨，研磨時間亦變長。 本發明係鑒於上述情況而完成者，其目的在於提供一種 可將研磨率控制為大致固定而研磨板狀體之板狀體之研磨 方法。 [解決問題之技術手段] 本發明提供一種板狀體之研磨方法，其係一面使板狀體 朝特定之方向移動，一面藉由自轉之研磨具研磨板狀體 者，其特徵在於··使上述研磨具之自轉方向在特定 點反轉。 立若宏觀上觀察將研磨具分離成本體（硬質部）與絨毛（軟質 部）來考慮，則實際研磨板狀體之絨毛藉由研磨或整 ^8796^00 201107077 而具有方向性。即，絨毛具有自研磨方向上游側朝下游侧 傾斜之方向性。若以具有此種方向性之狀態繼續研磨，則 絨毛相對於板狀體之旋轉阻力降低，因此研磨率將隨著研 磨時間流逝而降低。因此，當絨毛相對於板狀體之旋轉阻 力達到特定值以下時，即，當無法良好地實施利用絨毛之 研磨時，使研磨具於該時間點反轉。若如此，則絨毛在與 該反轉方向相反之方向上具有方向性，因此，接下來將一 面自板狀體受到較大之旋轉阻力，一面研磨板狀體。絨毛 最終欲使方向轉變為反轉之方向，但於絨毛受到特定之旋 轉阻力之研磨過程中，即，於絨毛之旋轉阻力超過特定值 之研磨過程令，藉由絨毛之旋轉阻力而使得研磨率上升。 基於上述驗證結果，本發明之特徵在於：當研磨具相對 於板狀體之旋轉阻力達到上述特定之旋轉阻力以下時，使 研磨具反轉。藉此，若使研磨具反轉則研磨率上升，又， 研磨率將緩慢地降低，但於研磨具之旋轉阻力達到特定值 以下時，使研磨具再次反轉而提昇研磨率。如此，基於自 板狀體所受到之研磨具之旋轉阻力而反覆進行研磨具之反 轉’藉此’研磨率不會大幅增減，因此可將研磨率控制為 大致固定而進行研磨。 ， 即，於本發明中，亦可形成為使上述研磨具之旋轉方向 以特定之週期反覆反轉之構成。 又，亦可形成為如下之構成，即預先設定與使上述研磨 具旋轉之馬達之負载電流值有關之下限值，監控研磨時之 負載電流之變化’於該負載電流值達到下限值之時間點使 148796.doc 201107077 上述研磨具之自轉方向反轉。 。由於研磨過程中不易直接測定研磨率，故而敎與研磨 率有關之馬達之負載電流值，當負載電流值達到特定值以 下時，即，當研磨具之旋轉阻力達到特定值以下時，使研 磨具之自轉方向反轉。藉此，根據本發明，可將研磨率控 制為大致固定。除此以外’，亦可每隔固定時間使研磨具之 自轉方向反轉。 又，本發明亦可形成為如下之構成，即上述研磨具以特 疋之公轉中心為中心而公轉，公轉方向於自轉方向反轉時 同時反轉。於自轉、公轉之研磨具之情形日夺，就使自轉軸 旋轉之轉矩與使公轉軸旋轉之轉矩的平衡關係而言，較佳 為與自轉方向反轉之同時公轉方向亦反轉。 又，本發明亦可形成為沿板狀體之移動方向而配置複數 台上述研磨具之構成。本發明之研磨具適用於連續式研磨 裝置。 又，本發明亦可形成為如下之構成，即包括整形步驟， 其係將上述研磨具壓至整形構件，並且使上述研磨具及上 述整形構件相對旋轉，對上述研磨具進行整形；且將上述 正^/步驟後所進行之上述板狀體之研磨時之上述研磨具的 自轉方向，設定成相對於上述整形步驟時之旋轉方向為反 方向。 本發明係關於研磨具之整形者。研磨具於板狀體之研磨 時疋期地藉由整形構件進行整形，於該整形步驟後所進行 之板狀體之研磨時，將研磨具之自轉方向設定成相對於整 148796.doc 201107077 形步戰時之旋轉方向為反方向。於整形時，研磨且 猎由研磨具與整形構件之相對旋轉而具有自、、’ 側朝下游側傾斜的方向性。因/向上游 域毛之傾斜方向使研磨具朝相反方向之 藉此，絨毛一面受到較大之旋轉 ·體， ^ 得阻力—面研磨板狀體。因 此，稭由該絨毛之旋轉阻力而使得板狀體之研磨率 又，本發明亦可形成為如下之構成，即，將上述整 =時之上述㈣構件與上述研磨具的相對旋轉方向，設定 方向。 ^之别之上述研磨具的自轉方向為同 古f據本發明，即將進行整形步驟之前之研磨具之絨毛且 ^ 月即將進行整形步驟之前之研磨具之自轉方向傾斜的特 於對此種研磨具進行整形時，將整形構件與研磨且之 相對旋轉方向設定成與即將進行整形步驟之前之研磨具 自轉方向為同方向，夢此於榦 、、 々Π a此於整形時可進一步增強賦予研 具之絨毛之方向性。即，可進—步增大絨毛之傾斜角度， b可進步增大整形步驟後所進行之研磨時之絨毛的旋 轉阻力，可大幅提昇板狀體之研磨率。 再者’所謂整形，係指將研磨具之作用面塵至金剛石磨 石等整形構件之表面，使整形構件及研磨具相對旋轉，藉 此獲取研磨具之作用面之擺動的操作、以及對經長時間^ 用之研磨具之作用面進行形狀修正的操作。 [發明之效果] 如以上所㈣般，根據本發明之板狀體之研磨方法，使 r c 7 148796.doc 201107077 研磨具之自轉方向在料定之時e 牡将疋<呀間點反轉，因此可將板狀體 之研磨率控制為大致固定。 【實施方式】 以下，依照隨附圖式，對本發明之板狀體之研磨方法的 較佳之實施形態進行說明。 圖1表示使用實施形態之板狀體之研磨方法之研磨裝置 10的鳥瞰圖。圖2係圖i所示之研磨裝置1〇的概略平面圖， ㈣中表示與研磨具12之形狀、配置位置以及動作有關的 内容。實施形態之研磨|置10係如下之裝置，卜面連續 搬送例如2200 mm(寬度）x2600 mm(長度）以上之尺寸之液 晶顯不器用玻璃基板G，—面藉由沿該搬送路徑所配置之 複數台圓形研磨具12、12··.連續研磨玻璃基板G。 如圖1所示，將研磨對象之玻璃基板G之與其研磨對象面 為相反側之面吸附保持在接著於平台14之未圖示之吸附片 材上，且如圖1、圖2之箭頭χ所示，藉由後述之搬送裝置 連續搬送平台14。而且，於平台14之搬送過程中，藉由設 置於上述搬送路徑之上方的複數台研磨機各自之研磨具 12、12…將研磨對象面研磨成液晶顯示器用玻璃基板〇所 要求之平坦度。再者，結束研磨之玻璃基板G係藉由清洗 裝置16而進行清洗。 如圖2所示，研磨具12、12…係由較玻璃基板G之寬度w 更小之直牷D構成，其藉由後述之研磨機之自轉/公轉機 構，以特定之旋轉中心為中心而旋轉，並且一面以特定之 公轉中心為中心而公轉，一面研磨玻璃基板G。再者，於 148796.doc 201107077 圖2中’實線所示之圓表示研磨具12、u...當前之姿勢， 雙點晝線所示之多個圓表示玻璃基板G與研磨具12、12... 接觸之部分之邊緣部。由該等圓亦可知，研磨具丨2、12... 係以特定之公轉中心為中心而公轉。 又，研磨具12、12…係以玻璃基板G之移動中心線L為基 準而成對地配置’並且配置成於移動方向上錯開位置之鋸 齒狀，且研磨具12、12...係以越過移動中心線L研磨玻璃 基板G之方式配置。 根據如此構成之連續式研磨裝置1〇，彙集複數台直徑D 小於玻璃基板G之寬度W的小型研磨具12 ,將該等研磨具 12、12…以玻璃基板G之移動中心線L為基準而左右成對地 配置’且研磨具12、12…越過中心線L而研磨玻璃基板G， 藉此可研磨玻璃基板G之整個面。 圖3係研磨機20之剖面結構圖。該研磨機2〇係以橫跨平 台14之方式設置。 首先’對平台14之搬送裝置進行說明，於平台14之下部 設置有一對導塊22、22，該導塊22、22係滑動自如地卡合 於配设在基台24上之一對導軌26、26。又，於平台14之下 部中央部’沿平台14之長度方向固定有支架28,且支架28 嚙合於小齒輪29。小齒輪29係旋轉自如地支樓於基台24 上’並且連結於未圖示之馬達之輸出轴，其藉由馬達之驅 動力而旋轉。藉此，將支架28傳送至小齒輪29，而以特定 之速度朝圖1、圖2所示之X方向搬送平台14。 藉由平台14之搬送’平台14上之吸附片材所保持的玻璃 148796.doc 201107077 基板G依次通過研磨機20、20…之下方，且於該通過過程 中被研磨機20、20.·.之研磨具12、12…一點點地研磨。而 且’最終製造液晶顯示器用玻璃基板所要求之平坦度者。 再者，平台14之搬送速度係控制為可根據研磨狀況而變 更。又’作為研磨具12，適用發泡聚胺酯墊、麂皮系墊 等，進而，於研磨時所供給之漿料中含有氧化鈽或氧化錯 等之游離研磨粒。 研磨機20係設置於平台14之上方，具有與平台14正交之 主軸30〇該主軸30經由上下配置之軸承32、32而旋轉自如 地支撐於本體套管34上，本體套管34係由配置於其兩側之 對柱36 ' 36固疋。又，於柱36、36之下部分別連結有設 置於基台24上之液壓千斤頂38的活塞4〇。因此，若活塞 40 40同枯進行伸縮動作，則經由柱3 6、3 6而使本體套管 34升降移動。藉此，具有研磨具12之研磨頭42相對於平台 1 4而沿上下方向進退移動。 另方面於主轴30形成有以相對於主軸3〇之軸心〇〗離 心之軸心〇2為中心軸的插通孔3〇A。於插通孔30A中插通 有輸出軸44,輸出軸44係以使其中心轴與上述轴心〇2 一致 式、由上下配置之轴承46 ' 46而旋轉自如地支撐於 主軸3 〇上。 。該齒輪4 8與齒輪5 0嗤 結。又，齒輪54經由惰 齒輪58係固定於公轉用 馬達60之驅動力經由齒 於主軸30之上周部設置有齒輪48 合，齒輪50經由軸52而與齒輪54連 齒輪56而與輸出齒輪58嚙合，輸出 馬達60之馬達輸出軸62上。藉此， 148796.doc •10- 201107077 輪58、=、54、50、48而減逮並傳遞至主㈣，因此主轴 。以特：之旋轉數紅轉。若主軸如上述般旋轉，則輸出 轴44將沿以主轴30之軸心〇 & & 釉〇1為中心的圓周而公轉。即，研 磨具12將以轴心Ql為中，d進行公轉運動。 輸出轴^下端部經由旋轉接頭64而與形成為圓形之研 磨頭42連結。研磨頭42包含上定盤^、研磨定盤^、研磨 具12、及空氣彈簧7〇、7〇等。 上定盤66料防止振動㈣剛性較高之残鋼製造。研 磨定盤68係禱鐵製或不鏽鋼製之高剛性結構，且經由空氣 彈菁而與上定盤66連結。上述空氣彈赞7〇、2 係以特定之間隔配設於以研磨頭4 2之轴芯〇 2為中心的圓周 上，並且經由形成於上定盤66之未圖示之空氣通路、及旋 轉接頭64而與未圖示之空氣系連結。因此’若將來自空氣 7 [縮工氣、..：由旋轉接碩64及空氣通路而供給至空氣彈 簧7〇、70..·，則空氣彈簧7〇、7〇 •膨騰。由此，空氣彈夢 7〇、7〇…之彈力經由研磨定盤68而傳遞至研磨具】2，因二 對研磨具12施加研磨壓力。ϋ ^ rTT ^ ^ 微&刀再者，該研磨壓力係藉由控制 供給至空氣彈簧70、70…之空氣屋力而進行調節。 另一方面，輸出軸44之上端部經由萬向接頭72而鱼自轉 用馬達74之輸出抽76連結。因此，藉由馬達74之驅動力， 輸出轴44以軸如2為中心*旋轉。即，研磨具12以轴心〇2 為中:進行自轉運動。再者’即便輸出轴44以袖心〇1為中 心進行公轉運動’亦由於輸出轴44經由萬向接頭U而與馬 達74之輸❹76連結，故而研磨具12將毫無障礙地進行自 J48796.doc 11 · 201107077 轉運動。 其次’對研磨機20之作用進行說明。 首先，使研磨機20之液壓千斤頂38之活塞4〇伸縮，藉此 使本體套官34上下移動，從而調整研磨頭42相對於平台14 之同度位置。而且，調整供給至空氣彈簧7〇之空氣量，針 對每台研磨機20、20...設定研磨壓力。 其次，朝搬送方向搬送平台14。而且，與此同時，分別 驅動研磨機20之公轉用馬達6〇及自轉用馬達74，一面使研 磨具12如圖4般以軸心〇1為中心進行公轉運動且以軸心〇2 為中心進行自轉運動，一面研磨由平台14搬送而來之玻璃 基板G。 如此，於研磨機20中，一面使研磨具12進行自轉公轉運 動一面研磨玻璃基板G，因此玻璃基板G係以研磨具12之 公轉執跡與自轉軌跡之複合執跡而受到研磨。由此，根據 並設複數台該研磨機2〇而構成之連續式研磨裝置1〇，可不 提幵研磨具12之公轉旋轉數，而提高研磨效率。又，亦無 需過度地提昇研磨具12之研磨壓力，因此玻璃基板G之研 磨面之平坦度亦得到提高。 然2，於先前之研磨裝置中，由於將研磨具之旋轉方向 僅設定為順時針方向或逆時針方向中的任一個方向，因此 隨著研磨時間之流逝，玻璃基板之研磨率降低。而且，若 研磨率低於特定之臨界值，則對其研磨墊進行整形。又右 於2前之研磨裝置中，即便於不必對研磨具進行整形之情 心柑，研磨率亦將隨著研磨時間之流逝而降低，因此無法 148796.doc 201107077 使研磨率大致固定來連續地研磨。 實施形態之研磨裝置1 〇係以消除先前之研磨裝置所具有 之缺點、將研磨率控制為大致固定來研磨玻璃基板為目的 而完成者。即，利用實施形態之研磨裝置10之研磨方法係 使研磨具12之自轉方向在特定之時間點反轉。 對若使研磨具12反轉，則可將研磨率控制為大致固定之 理由進行說明。 如圖5A所示，若宏觀上觀察將研磨具12分離為研磨具基 底（硬質部）12A與絨毛（軟質部）12B來考慮，則實際研磨玻 璃基板G之絨毛12B藉由研磨或整形等而具有方向性。 即，絨毛12B如圖5B所示，當自研磨具朝玻璃基板〇方向 觀察時，朝與研磨方向（grinding directi〇n)相反之方向傾 斜。若以具有此種方向性之狀態繼續研磨，則絨毛l2B相 對於玻璃基板G之旋轉阻力降低，因此研磨率將隨著研磨 時間之流逝而降低。因此，當絨毛12B相對於玻璃基板G 之旋轉阻力達到特定值以下時’ &，當利用絨毛ΐ2β之研 磨無法良好地實施時，在該時間點使研磨具12之自轉方向 反轉。若如此，則絨毛12B如圖5(：般在與該反轉方向相反 U向上具有方向’因此’接下來將—面自玻璃基板G 党到較大之阻々（resistance increases，阻力增大），一面研 磨玻璃基板^絨毛〗2B如圖5D所示，最終欲使方向轉變 為反轉之方向，但於絨毛12B受到特定之旋轉阻力之研磨 過程卜Ί織毛12B之旋轉阻力超過特定值之研磨過 程中，藉由絨毛之上述旋轉阻力而使得研磨率上升。 148796.doc -13· 201107077 基於上述驗證結果，於實施形態之研磨方法令，當研磨 具12相對於玻璃基板G之旋轉阻力達到上述特定之阻力以 下時，使研磨具12之自轉方向自正轉（n〇rmal r〇tati〇n)起倒 轉（reverse rotation)而反轉。藉此，若使研磨具12反轉， 則研磨率（grinding rate)上升，又，研磨率將緩慢地降低’ 但於研磨具12之旋轉阻力達到特定值以下時，使研磨具Η 再次反轉而提昇研磨率。如此，基於自玻璃基板〇所受到 之研磨具12之旋轉阻力而反覆進行研磨具12之反轉，藉 此，研磨率不會大幅增減，因此可將研磨率控制為大致固 定而進行研磨。 根據貝施形態之研磨方法，如圖6所示之圖表般，當使 研磨具12旋轉之馬達74(參照圖3)之負載電流值（1〇ad current value)達到特定值（TH值）以下時，使研磨具12之自 轉方向反轉。即，實施形態之研磨裝置1〇包含控制部，該 控制部於馬達74(參照圖3)之負載電流值達到特定值（TH值） 以下時使研磨具12之自轉方向反轉。再者，亦可於玻璃基 板G之研磨過程中直接測定研磨率’並根據研磨率而使研 磨具12之旋轉方向反轉，但由於玻璃基板〇之研磨過程中 不易直接測定研磨率’故而測定與研磨率有關之馬達74之 自轉電流值’並根據該電流值使研磨具丨2反轉。 若對圖6之圖表進行說明’則橫轴為時間轴，右縱軸表 示馬達74之自轉電流值。該自轉電流值於以特定之電壓驅 動馬達時’可根據負載之狀態而變動，因此亦被稱為負載 電流值。左縱軸表示研磨率（單位：pm/min)。又，根據圖 I48796.doc -14- 201107077 6 ’將用以切換馬達74之旋轉方向之自轉電流值的臨界值 設定成特定之下限值（圖中之TH值）。 自轉電流值之臨界值較佳為反轉之後不久之自轉電流值 的65%之電流值。更佳為70%之電流值，特佳為8〇%之電 流值。 又’於每隔固定時間使研磨具之自轉方向反轉之情形 時，可將自反轉之後不久至達到上述自轉電流值之臨界值 為止所需之時間的最短時間作為反轉之間隔。藉由如此決 定反轉時間，即便自反轉之後不久至達到上述自轉電流值 之fem界值為止所需的時間存在偏差，亦可使研磨率大致固 定。 進而，該實驗例係將自轉旋轉數、公轉旋轉數、研磨具 12相對於玻璃基板(3之壓力、以及漿料供給量分別設定成 特定值而實施者。 如該圖所示’於本發明中，以如下方式設定馬達之驅動 控制：若自轉電流值達到TH值以下，則使馬達74自正轉 反轉為倒轉、自倒轉反轉為正轉。因此，如該圖之圖表所 示’自轉電流值（研磨率）上升，然後，隨著研磨時間之流 逝’自轉電流值（研磨率）將下降。而且，若該自轉電流再 次達到TH值以下，則馬達74反轉，因此自轉電流值（研磨 率）將再次上升。如此，自轉電流值與研磨率具有正㈣ 關係。、而且，直接設定可控制之自轉電流值之臨界值阳 值）’並根據該臨界值而使利用馬達74之研磨具12之自轉 方向反轉。藉由該構成’可控制該圖所示之研磨率之上下 [S ] 148796.doc -15- 201107077 變動（條形圖）之程度，將研磨率控制為大致岐而進行控 制。 又，根據實施形態之研磨方法，上述控制部亦控制馬達 6〇’於研磨具12之自轉方向反轉時同時亦使研磨具12之公 轉方向反轉。於如實施形態之研磨機2〇般使研磨具η自 轉、公轉之裝置的情形時，就使自轉軸(輸出轴44 :參照 圖3)旋轉之轉矩與使公轉軸(主軸3〇:參照圖3)旋轉之轉矩 的平衡關係而言.，較佳為與自轉方向反轉之同時公轉方向 亦反轉。 再者，於實施形態中，對並設有複數台研磨機2〇之連續 式研磨裝置10進行了說明，但亦可將本發明之研磨方法用 於包含1台研磨機20之研磨裝置，又，對研磨具12自轉及 公轉之研磨機20進行了說明，但亦可將本發明之研磨方法 用於研磨具12僅進行自轉之研磨裝置。 於上述實施例中，對使研磨具12之自轉方向、公轉方向 在特定之時間點反轉，而將玻璃基板G之研磨率控制為大 致固定之例進行了敍述。相對於此，於定期實施之研磨具 12之整形中，亦可藉由著眼於整形之後不久之研磨具丨二的 自轉方向、及即將進行整形之前的研磨具丨2之自轉方向， 而提昇玻璃基板G之研磨率。 即’實施形態之研磨方法包括整形步驟。所謂整形步 驟，如圖7A所示’係指將研磨具12壓至整形構件8〇，並且 使研磨具12及整形構件80相對自轉或自公轉，而對研磨具 12進行整形之步驟。再者，於圖7A中，相對於固定之敕形 148796.doc •16· 201107077 構件80’使研磨具12朝箭頭A方向自轉或自公轉而實施整 形，但亦可固定研磨具12，使整形構件8〇自轉或自公轉， 亦可使研磨具12及整形構件8〇兩者自轉。作為整形構件 80，可例示構成為圓盤狀或矩形狀之金剛石磨石。 如圖7B所示’提昇研磨率之一例係將整形步驟後所進行 之玻璃基板G之研磨時之研磨具12的以箭頭B表示之自轉 方向，設定成相對於圖7A所示之整形步驟時的以箭頭八表 示之自轉方向為反方向。 研磨具12係於玻璃基板G之研磨時定期地由整形構件肋 進行整形，於該整形步驟後所進行之破璃基板〇之研磨 時，將研磨具12之自轉方向設定成相對於整形步驟時之自 轉方向為反方向。 如圖7A所示，於整形時，研磨具12之織毛咖藉由研磨 具12與整形構件80之相對旋轉而具有自整形方向上游侧朝 下游側傾斜（傾斜角度Θ2)之方向性。由此，相對於整形時 所產生之絨毛12B之傾斜方向，使研磨具12朝反方向自轉 而研磨玻璃基板G。藉此，如圖7B所示，絨毛nB一面受 到較大之旋轉阻力一面研磨玻璃基板〇。因此，藉由該絨 毛12B之旋轉阻力而使玻璃基板〇之研磨率上升。 使用示意性地表示之圖8之圖表來進行具體說明。 該圖之圖表之橫軸t為時間軸，左縱軸表示研磨率（單 位：μιη/min)。如該圖表所示，使研磨具12反覆正轉、反 轉而實施玻璃基板G之研磨，於該研磨步驟之時間點（a)， 如圖7A所示實施研磨具12之整形。其後，如圖7B所示， 148796.doc •17- 201107077 將研磨具12之自轉方向設定成相對於整形時之方向 向，繼續進行玻璃基板G之研磨。如圖8之圖表所二Y。方 整形後之研磨率之峰值（a)相對於利用通常之正 ，匕 评、反轉動 作之研磨率之峰值（b)大幅上升。 作為比較例’使用圖9之圖表來進行說明。 於该比較例中’使整形時之研磨具12之自轉方向與整形 之後不久的研磨具之自轉方向相同。根據該比較例 知藉由利用時間點（A)之整形之研磨具12的整形，整形之 後不僅的研磨率之峰值自b值上升至(；值，其上升量（〇值— b值）少於圖8所示之實施例之上升量（&值—b值）。 而且，於圖7A及7B之實施例中，在研磨具以為新品之 狀態、或剛修整後的狀態下可獲得較大之效果。然而，若 長時間持續使用研磨具12，則藉由整形無法使利用研磨而 退回之絨毛12B之捲曲充分地退回，而無法大幅提昇研磨 率。 即，如圖10A所示，於整形時使研磨具12朝箭頭A方向 自轉’於其後不僅所貫施之研磨時，如圖】所示’使研 磨具12朝箭頭B方向反轉。若於此狀態下繼續研磨後，則 如圖10C所示’研磨具12之絨毛12β沿研磨方向傾斜，其 結果’研磨率將降低。而且，如圖丨0D所示，即便於其後 朝箭頭A方向實施整形，亦無法使藉由研磨而退回之絨毛 12B之捲曲退回至如圖i〇A之狀態。由此，無法提昇其後 不久所實施之研磨之研磨率。 於此情形時’將整形步驟時之整形構件與研磨具12之相 148796.doc •18- 201107077 :旋轉方向’設定成與即將進行整形步驟之前之研磨具i2 的自轉方向為同方向。 即將進行整形步驟之前之研磨具12之織毛i2b具有朝即 將進行整形步驟之前之研磨具12之自轉方向傾斜的特性。 於對上述研磨具12進行整形時’將整形構件與研磨具12之 相對旋轉方向’設定成與即將進行整形步驟之前之研磨具 12的自轉方向為同方向，藉此於整形時可進一步增強賦予 研磨具12之絨毛12B的方向性。即，如圖nA所示，可使 絨毛12B之傾斜角度θι大於圖M所示之傾斜角度心，因 此’如圖11B所示，可進-步增大整形步驟後使研磨具^ 反轉時之織毛12B之旋轉阻力。由此’可大幅提昇玻璃基 板G之研磨率。 再者，圖llAt以箭頭B表示整形方向，圖UB中以箭頭 A表示研磨方向。即，揭示了相對於圖及川、圖i〇A〜 10D，使整形方向反轉，亦使其後不久所實施之研磨具12 之自轉方向反轉的例子。 使用示意性地表示之圖12之圖表來進行具體說明。 S亥圖之圖表之檢軸t為時間軸，左縱轴表示研磨率（單 位：μιη/min)。如該圖表所示，使研磨具12反覆正轉、反 轉而實施玻璃基板G之研磨，於該研磨步驟之時間點（A)、 (B)實施圖7A所示之整形。然後，於其後之時間點（c)實施 圖11A所示之整形後，如圖iiB所示’使研磨具12反轉而 繼續研磨。藉此’如圖12之圖表所示，可知圖"A之整形 後之研磨率的峰值（d)相對於之前之研磨率的值大幅上 148796.doc •19- 201107077 再者，其後於時間點（D)、（e)所實施之整形係隨及 1形即’圖11A所示之整形亦可於每次整形時 貫$，但較佳為於研料低於特定值時間歇 必要時實施。 詳細且參照特定之訾 貫知瓜態對本申請案進行了說明，但 對於本領域從業人員 ^ ^ C 了明確.可不脫離本發明之精 神與範圍而加以各種蠻争赤 種變更或修改。本申請案係基於2009年 6月4曰申請之曰本專利申妹 号不j甲°月（日本專利特願2009-135108) 者，其内容以參照之形式併入本文中。 [產業上之可利用性] 【圖式簡單說明】 利用本發明之板狀體之研磨裝置的研磨對象物並不限定 於FPD用破璃基板，亦可將建材用或鏡料之—般玻璃板 作為對象，又’亦可將金屬製板㈣作為對象。 圖1係實施形態之玻璃基板研磨裝置之鳥瞰圖。 圖2係圖1所示之研磨裝置的主要部分平面圖。 圖3係說明圖丨所示之研磨裝置之研磨機之結構的縱剖面 圖。 圖4係表示圖3所示之研磨機之研磨具之公轉轨跡的圖。 圖5A係表示研磨具相對於玻璃基板之旋轉阻力的圖。 圖5B係表示研磨具相對於玻璃基板之旋轉阻力的圖。 圖5C係表示研磨具相對於玻璃基板之旋轉阻力的圖。 圖5D係表示研磨具相對於玻璃基板之旋轉阻力的圖。 圖ό係表示馬達之自轉電流值與研磨率之關係的圖表。 148796.doc -20- 201107077 圖7A係對表示提昇研磨率 夕f結明& 例之研磨具與整形構件 之方疋轉關係加以表示的說明圖。 圖7B係對表示提昇研磨率 夕诧絲朗/ 例之研磨具與整形構件 之紋轉關係加以表示的說明圖。 圖8係表示使研磨具於整形後反 研磨率之變化的圖表。 圖9係表示不使研磨具於整形後反轉 之研磨率之變化的圖表。 圖10A係表示由繼續使用研磨具所 說明圖。 轉而研磨玻璃基板時 之 而研磨玻璃基板時 弓丨起之絨毛之捲曲的 圖10B係表示由繼續使用研磨具所 說明圖。 弓丨起之絨毛之捲曲的 圖10C係表示由繼續使用研 說明圖。 磨具所引起之絨毛之捲曲的 研磨具所引起之絨毛之捲曲的 圖1 〇D係表示由繼續使用 5兄明圖。 例之研磨具與整形構 圖11A係對表示提昇研磨率之第 件之紅轉關係加以表示的說明圖。 圖1丨B係對表示提昇研磨率 _ 件之旋轉關係加以表示的說明圖厂^磨具與整形構 轉方圖將整形步驟時之整形構件與研磨具之相對旋 向為與即將進行整形料之前之研磨具的自轉方 。方向日宁之研磨率之變化的圖表。 【主要元件符號說明】 I48796.doc 201107077 10 研磨裝置 12 研磨具 12A 研磨具基底 12B 織毛 14 平台 16 清洗裝置 20 研磨機 22 導塊 24 基台 28 支架 29 小齒輪 30 主轴 32 軸承 34 本體套管 36 .柱 38 液壓千斤頂 40 活塞 42 研磨頭 44 輸出軸 46 軸承 48 齒輪 50 齒輪 52 軸 54 齒輪 -22 148796.doc 201107077 56 惰齒輪 58 輸出齒輪 60 公轉用馬達 62 馬達輸出軸 64 旋轉接頭 66 上定盤 70 空氣彈簧 72 萬向接頭 74 自轉用馬達 76 輸出軸 80 整形構件 148796.doc -23-BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of polishing a plate-shaped body, and more particularly to an FpD (Flat Panel Display 'flat panel display) used for polishing a liquid crystal display or the like by a polishing apparatus. A method of polishing a plate-shaped body of a glass substrate. [Prior Art] A glass substrate for an FPD used in a liquid crystal display or the like is formed by forming a molten glass into a plate shape by a glass method called a floating method, and the continuous polishing apparatus disclosed in Patent Document 1 or the like The polishing is performed to remove minute irregularities or undulations on the surface thereof, thereby producing a thin plate having a thickness of approximately 〇·4 to ι·ι mm which satisfies the flatness required for the glass substrate for liquid crystal display. In such a continuous polishing apparatus, as described in Patent Document 2, a glass substrate is generally polished by a polishing pad (abrasive tool) that rotates and revolves. In the conventional continuous polishing apparatus, the surface of the glass substrate opposite to the surface to be polished is adsorbed and held on the adsorption sheet attached to the stage, and the glass substrate is continuously conveyed by the transfer apparatus of the transfer platform. The polishing target surface is sequentially polished by a polishing pad of a plurality of polishing machines disposed above the transfer path. The polishing pad is rotated by a rotation/revolution mechanism centering on a special rotation center, and is revolved around a specific revolution center to polish the glass substrate. X, when using a rectangular grinding ’, only the revolving motion is performed. As a continuous polishing apparatus using a rectangular polishing pad, there is a continuous polishing apparatus including only a rectangular polishing crucible, or a combination of a rectangular polishing crucible and a polishing pad of a shape of 148796.doc 201107077. Continuous grinding device. [Prior Art Document] [Patent Document 1] Japanese Laid-Open Patent Publication No. 2007-190657 [Patent Document 2] Japanese Patent Laid-Open Publication No. 2001-29365 No. The previous grinding device has the following problem: as the polishing time elapses, the polishing rate of the glass substrate will decrease. If the polishing rate is lower than a certain critical value, the polishing pad needs to be shaped or trimmed, so that the glass substrate cannot be lifted. Production efficiency. Moreover, the prior art polishing apparatus has a problem that even if it is not necessary to shape or trim the polishing tool, the polishing rate will decrease as the polishing time elapses, so that the polishing rate cannot be substantially fixed and continuously polished. The grinding time also becomes longer. The present invention has been made in view of the above circumstances, and an object of the invention is to provide a method of polishing a plate-like body in which a polishing rate is controlled to be substantially constant and a plate-like body is polished. [Technical means for solving the problem] The present invention provides a method for polishing a plate-shaped body, which is characterized in that the plate-shaped body is moved in a specific direction while the plate-shaped body is polished by a rotating abrasive tool, and is characterized in that The rotation direction of the above-mentioned abrasive tool is reversed at a specific point. If the macroscopic observation is to consider the separation of the abrasive body (hard part) and the fluff (soft part), the fluff of the actual plate-like body is directional by grinding or grinding. That is, the pile has a directivity which is inclined from the upstream side toward the downstream side in the grinding direction. If the polishing is continued in such a state of directionality, the rotational resistance of the fluff to the plate-like body is lowered, so that the polishing rate is lowered as the grinding time elapses. Therefore, when the rotational resistance of the pile relative to the plate-like body reaches a certain value or less, that is, when the grinding using the pile is not performed satisfactorily, the grinding tool is reversed at this point of time. In this case, the fluff has directivity in a direction opposite to the reverse direction, and therefore, the plate-like body is polished while receiving a large rotational resistance from the plate-like body. The fluff finally wants to change the direction to the direction of reversal, but in the grinding process in which the fluff is subjected to a specific rotational resistance, that is, the grinding process in which the rotational resistance of the fluff exceeds a certain value, the grinding rate is caused by the rotational resistance of the fluff. rise. Based on the above verification results, the present invention is characterized in that the polishing tool is reversed when the rotational resistance of the polishing tool with respect to the plate-like body reaches the above-described specific rotational resistance. As a result, when the polishing tool is reversed, the polishing rate is increased, and the polishing rate is gradually lowered. However, when the rotation resistance of the polishing tool is equal to or lower than a specific value, the polishing tool is reversed again to increase the polishing rate. In this way, the polishing tool is reversely rotated based on the rotational resistance of the polishing tool received from the plate member. The polishing rate is not greatly increased or decreased. Therefore, the polishing rate can be controlled to be substantially constant and polished. That is, in the present invention, the rotation direction of the polishing tool may be reversely reversed at a specific cycle. Further, a configuration may be adopted in which a lower limit value associated with a load current value of a motor for rotating the polishing tool is set in advance, and a change in load current during polishing is monitored to a lower limit value of the load current value. The time point makes 148796.doc 201107077 the rotation direction of the above grinding tool reversed. . Since it is not easy to directly measure the polishing rate during the grinding process, the load current value of the motor related to the polishing rate is such that when the load current value reaches a certain value or less, that is, when the rotational resistance of the polishing tool reaches a certain value or less, the abrasive tool is used. The rotation direction is reversed. Thereby, according to the present invention, the polishing rate can be controlled to be substantially constant. In addition to this, the rotation direction of the polishing tool can be reversed every fixed time. Further, the present invention may be configured such that the polishing tool revolves around the center of the revolving center, and the revolving direction is reversed simultaneously when the rotation direction is reversed. In the case of the grinding tool for the rotation and the revolution, the balance between the torque of the rotation of the rotation shaft and the torque for rotating the revolution shaft is preferably reversed while the rotation direction is reversed. Further, the present invention may be configured such that a plurality of the above-described polishing tools are arranged along the moving direction of the plate-like body. The abrasive article of the present invention is suitable for use in a continuous grinding apparatus. Furthermore, the present invention may be configured to include a shaping step of pressing the polishing tool to the shaping member, and rotating the polishing tool and the shaping member to shape the polishing tool; The direction of rotation of the polishing tool during polishing of the plate-shaped body performed after the step is set to be opposite to the direction of rotation in the shaping step. The present invention relates to a shaper of an abrasive tool. The grinding tool is shaped by the shaping member during the grinding of the plate-shaped body. When the plate-shaped body is polished after the shaping step, the rotation direction of the grinding tool is set to be relative to the whole shape. The direction of rotation during the battle is in the opposite direction. At the time of shaping, the grinding and hunting are directional with respect to the downstream side by the relative rotation of the grinding tool and the shaping member. Because of the tilting direction of the upstream hair, the grinding tool is oriented in the opposite direction, and the fluff is subjected to a large rotation, and the resistance is a surface-grinding plate-like body. Therefore, the polishing rate of the sheet body by the rotation resistance of the pile is further increased, and the present invention may be configured to set the relative rotation direction of the above-mentioned (four) member and the above-mentioned polishing tool. direction. The rotation direction of the above-mentioned grinding tool is the same as that of the present invention, the fluff of the grinding tool before the shaping step is performed, and the rotation direction of the grinding tool before the shaping step is about to be inclined. When the shaping is performed, the relative rotation direction of the shaping member and the grinding is set to be the same direction as the rotation direction of the polishing tool immediately before the shaping step, and the dream can be further enhanced when the shaping is performed. The directionality of the fluff. That is, the inclination angle of the pile can be further increased, and b can be used to increase the rotation resistance of the pile during the grinding after the shaping step, and the polishing rate of the sheet body can be greatly improved. In addition, the term "shaping" refers to the operation of the surface of the shaping member such as the diamond grindstone and the relative rotation of the shaping member and the polishing tool, thereby obtaining the operation of the swinging of the action surface of the abrasive tool and the The shape correction operation is performed on the action surface of the abrasive tool for a long time. [Effects of the Invention] As described in the above (4), according to the method for polishing a plate-shaped body of the present invention, the direction of rotation of the rc 7 148796.doc 201107077 abrasive tool is reversed at the time of the determination of the e-mud. Therefore, the polishing rate of the plate-like body can be controlled to be substantially constant. [Embodiment] Hereinafter, preferred embodiments of the method for polishing a plate-shaped body of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a bird's eye view showing a polishing apparatus 10 using a polishing method of a plate-like body of an embodiment. Fig. 2 is a schematic plan view of the polishing apparatus 1A shown in Fig. i, and (4) shows the shape, arrangement position, and operation of the polishing tool 12. In the polishing method of the embodiment, the following apparatus is used, and the glass substrate G for liquid crystal display of the size of 2200 mm (width) x 2600 mm (length) or more is continuously conveyed on the surface, and the surface is placed along the transport path. The circular polishing tool 12, 12... continuously polishes the glass substrate G. As shown in FIG. 1, the surface of the glass substrate G to be polished on the opposite side to the surface to be polished is adsorbed and held on an adsorption sheet (not shown) following the stage 14, and as shown in FIG. 1 and FIG. As shown in the figure, the platform 14 is continuously conveyed by a conveying device to be described later. Further, during the conveyance of the stage 14, the polishing target 12, 12, ... of each of the plurality of polishing machines disposed above the transfer path polishes the surface to be polished into the flatness required for the glass substrate for liquid crystal display. Further, the glass substrate G which has been polished is cleaned by the cleaning device 16. As shown in FIG. 2, the polishing tools 12, 12, ... are composed of a straight line D which is smaller than the width w of the glass substrate G, and is centered on a specific rotation center by a rotation/revolution mechanism of a grinder to be described later. The glass substrate G is ground while rotating around the center of the specific revolution center. Furthermore, in 148796.doc 201107077, the circle indicated by the solid line in FIG. 2 indicates the current posture of the polishing tool 12, u..., and the plurality of circles indicated by the double-pointed line indicate the glass substrate G and the polishing tool 12, 12... The edge of the part that touches. It can also be seen from the circles that the grinding tools 2, 12, ... are revolved around a specific revolution center. Further, the polishing tools 12, 12, ... are arranged in a zigzag manner with respect to the movement center line L of the glass substrate G, and are arranged in a zigzag shape shifted in the moving direction, and the polishing tools 12, 12, ... are The glass substrate G is polished over the moving center line L. According to the continuous polishing apparatus 1A configured as described above, a plurality of small-sized polishing tools 12 having a diameter D smaller than the width W of the glass substrate G are collected, and the polishing tools 12, 12, ... are based on the movement center line L of the glass substrate G. The glass substrates G are polished by the polishing tools 12, 12, ... and the polishing tools 12, 12, ..., and the entire surface of the glass substrate G can be polished. 3 is a cross-sectional structural view of the grinder 20. The grinder 2 is disposed across the platform 14. First, the conveying device of the platform 14 will be described. A pair of guide blocks 22 and 22 are provided at the lower portion of the platform 14, and the guide blocks 22 and 22 are slidably engaged with a pair of guide rails 26 disposed on the base 24. 26. Further, a bracket 28 is fixed to the center portion of the lower portion of the platform 14 along the longitudinal direction of the platform 14, and the bracket 28 is engaged with the pinion gear 29. The pinion gear 29 is rotatably supported on the base 24 and is coupled to an output shaft of a motor (not shown) which is rotated by the driving force of the motor. Thereby, the holder 28 is conveyed to the pinion gear 29, and the stage 14 is conveyed in the X direction shown in Figs. 1 and 2 at a specific speed. The glass held by the adsorbing sheet on the platform 14 by the platform 14 is 148796.doc 201107077. The substrate G passes sequentially under the grinders 20, 20, ... and is passed by the grinders 20, 20. The grinding tools 12, 12... are ground a little bit. Moreover, the flatness required for the glass substrate for liquid crystal display is finally produced. Further, the conveying speed of the stage 14 is controlled so as to be changeable according to the grinding condition. Further, as the polishing tool 12, a foamed polyurethane pad, a suede pad or the like is used, and further, the slurry supplied at the time of polishing contains free abrasive grains such as cerium oxide or oxidization. The grinder 20 is disposed above the platform 14 and has a main shaft 30 orthogonal to the platform 14 . The main shaft 30 is rotatably supported on the main body sleeve 34 via bearings 32 and 32 disposed above and below. The main body sleeve 34 is The pair of posts 36' 36 disposed on both sides thereof are fixed. Further, pistons 4A of hydraulic jacks 38 provided on the base 24 are coupled to the lower portions of the columns 36, 36, respectively. Therefore, when the piston 40 40 performs the expansion and contraction operation, the main body sleeve 34 is moved up and down via the columns 36 and 36. Thereby, the polishing head 42 having the polishing tool 12 moves forward and backward in the vertical direction with respect to the stage 14. On the other hand, the main shaft 30 is formed with an insertion hole 3A having a center axis θ with respect to the axis of the main shaft 3〇. An output shaft 44 is inserted into the insertion hole 30A, and the output shaft 44 is rotatably supported by the main shaft 3 由 by a bearing 46' 46 disposed such that the center axis thereof coincides with the shaft center 〇2. . The gear 48 is coupled to the gear 50. Further, the driving force of the gear 54 fixed to the revolution motor 60 via the idle gear 58 is provided with a gear 48 via the tooth on the upper circumference of the main shaft 30, and the gear 50 is coupled to the gear 54 via the shaft 52 to the gear 56 and the output gear 58. Engaged, output motor 60 on motor output shaft 62. By this, 148796.doc •10-201107077 rounds 58,=, 54, 50, 48 are reduced and passed to the main (four), hence the main axis. Take special: the number of rotations turns red. If the spindle rotates as described above, the output shaft 44 will revolve along the circumference centered on the axis amp && glaze 1 of the spindle 30. That is, the grinding tool 12 will rotate in the center of the axis Q1 and d. The lower end of the output shaft is coupled to the grinding head 42 formed in a circular shape via a rotary joint 64. The polishing head 42 includes an upper plate ^, a polishing plate ^, a grinding tool 12, and air springs 7, 7 and the like. The upper plate 66 is used to prevent vibration (4) the production of residual steel with high rigidity. The grinding plate 68 is of a highly rigid structure made of iron or stainless steel and is coupled to the upper plate 66 via air-elastic. The air bombs 7 and 2 are disposed at a predetermined interval on a circumference centered on the core 〇 2 of the polishing head 4 2, and are rotated through an air passage (not shown) formed in the upper plate 66. The joint 64 is coupled to an air system (not shown). Therefore, if the air is supplied from the air 7 to the air springs 7〇, 70.., the air springs 7〇, 7〇, and so on. As a result, the elastic force of the air bombs 7 to 7 is transmitted to the polishing tool 2 via the polishing plate 68, and the polishing force is applied to the polishing tool 12. ϋ ^ rTT ^ ^ Micro & Knife Again, the grinding pressure is adjusted by controlling the air supply force supplied to the air springs 70, 70.... On the other hand, the upper end portion of the output shaft 44 is coupled to the output of the fish rotation motor 74 via the universal joint 72. Therefore, the output shaft 44 is rotated about the axis such as 2 by the driving force of the motor 74. That is, the grinding tool 12 is centered on the axis 〇2: the rotation motion is performed. Furthermore, even if the output shaft 44 revolves around the sleeve 〇1, since the output shaft 44 is coupled to the feed 76 of the motor 74 via the universal joint U, the abrasive tool 12 will be carried out without any obstacle from J48796. Doc 11 · 201107077 Turn to exercise. Next, the action of the grinder 20 will be described. First, the piston 4 of the hydraulic jack 38 of the grinder 20 is telescoped, whereby the body sleeve 34 is moved up and down, thereby adjusting the position of the grind head 42 with respect to the platform 14. Further, the amount of air supplied to the air spring 7 is adjusted, and the polishing pressure is set for each of the grinders 20, 20, .... Next, the platform 14 is transported in the transport direction. At the same time, the revolving motor 6 〇 and the rotation motor 74 of the grinder 20 are driven to revolve around the axis 〇 1 as shown in FIG. 4 and center on the axis 〇 2 The glass substrate G conveyed by the stage 14 is polished while performing the rotation motion. As described above, in the grinder 20, the glass substrate G is polished while the polishing tool 12 is rotated and revolved. Therefore, the glass substrate G is polished by the composite track of the polishing tool 12 and the rotation track. Therefore, the continuous polishing apparatus 1A configured by arranging a plurality of the polishing machines 2〇 can improve the polishing efficiency without mentioning the number of revolutions of the polishing tool 12. Further, since it is not necessary to excessively increase the polishing pressure of the polishing tool 12, the flatness of the polishing surface of the glass substrate G is also improved. However, in the conventional polishing apparatus, since the rotation direction of the polishing tool is set to only one of the clockwise direction and the counterclockwise direction, the polishing rate of the glass substrate is lowered as the polishing time elapses. Moreover, if the polishing rate is below a certain critical value, the polishing pad is shaped. In the polishing apparatus right before 2, even if it is not necessary to shape the polishing tool, the polishing rate will decrease as the polishing time elapses, so that the polishing rate can be substantially fixed continuously. Grinding. The polishing apparatus 1 of the embodiment is intended to eliminate the disadvantages of the prior polishing apparatus and to control the polishing rate to be substantially fixed to polish the glass substrate. That is, the polishing method of the polishing apparatus 10 of the embodiment reverses the direction of rotation of the polishing tool 12 at a specific time point. The reason why the polishing rate can be controlled to be substantially constant when the polishing tool 12 is reversed will be described. As shown in FIG. 5A, when the polishing tool 12 is separated into the polishing tool base (hard portion) 12A and the fluff (soft portion) 12B as viewed macroscopically, the fluff 12B of the actual polished glass substrate G is polished or shaped. Directional. That is, as shown in Fig. 5B, the pile 12B is inclined in a direction opposite to the grinding direction when viewed from the direction in which the polishing tool faces the glass substrate. When the polishing is continued in such a state of directionality, the rotational resistance of the fluff 122 with respect to the glass substrate G is lowered, so that the polishing rate is lowered as the polishing time elapses. Therefore, when the rotational resistance of the pile 12B with respect to the glass substrate G reaches a certain value or less, &>, when the grinding by the pile 2β is not performed satisfactorily, the rotation direction of the polishing tool 12 is reversed at this point of time. If so, the pile 12B has a direction as shown in FIG. 5 (in the U direction opposite to the reverse direction), so that the surface is subsequently increased from the glass substrate G to the resistance increase (resistance increased). , one side of the ground glass substrate, the fluff, 2B, as shown in Fig. 5D, finally wants to change the direction to the direction of reversal, but in the grinding process in which the fluff 12B is subjected to a specific rotational resistance, the grinding resistance of the woven wool 12B exceeds a certain value. In the process, the polishing rate is increased by the above-described rotational resistance of the pile. 148796.doc -13· 201107077 Based on the above verification result, the polishing method of the embodiment is such that the rotation resistance of the polishing tool 12 with respect to the glass substrate G reaches the above When the specific resistance is equal to or lower than the specific resistance, the rotation direction of the polishing tool 12 is reversed from the forward rotation (n〇rmal r〇tati〇n) and reversed. Thus, if the polishing tool 12 is reversed, the polishing rate is When the (grinding rate) rises, the polishing rate will decrease slowly. 'But when the rotational resistance of the polishing tool 12 reaches a certain value or less, the polishing tool 再次 is reversed again to increase the polishing rate. Since the polishing tool 12 is reversed from the rotation resistance of the polishing tool 12 received by the glass substrate ,, the polishing rate is not greatly increased or decreased, so that the polishing rate can be controlled to be substantially constant and polished. In the polishing method of the form, when the load current value (1〇ad current value) of the motor 74 (refer to FIG. 3) for rotating the polishing tool 12 is equal to or less than a specific value (TH value), the pattern is as shown in FIG. The polishing apparatus 1 of the embodiment is reversed. That is, the polishing apparatus 1A of the embodiment includes a control unit that causes the polishing tool 12 when the load current value of the motor 74 (see FIG. 3) reaches a specific value (TH value) or less. The rotation direction is reversed. Further, the polishing rate can be directly measured during the polishing process of the glass substrate G, and the rotation direction of the polishing tool 12 is reversed according to the polishing rate, but it is not easy to directly in the polishing process of the glass substrate The polishing rate is measured, so that the rotation current value of the motor 74 is measured in accordance with the polishing rate, and the polishing tool 丨2 is reversed based on the current value. If the graph of Fig. 6 is described, the horizontal axis is the time axis and the right vertical axis. Table The value of the rotation current of the motor 74 is shown. The value of the rotation current is variable according to the state of the load when the motor is driven at a specific voltage, and is therefore also referred to as the load current value. The left vertical axis indicates the polishing rate (unit: pm/min) Further, according to the figure I48796.doc -14- 201107077 6 'the threshold value of the rotation current value for switching the rotation direction of the motor 74 is set to a specific lower limit value (TH value in the figure). The threshold value is preferably a current value of 65% of the value of the spin current shortly after the inversion, more preferably a current value of 70%, particularly preferably a current value of 8〇%. Further, in the case where the rotation direction of the polishing tool is reversed every fixed time, the shortest time from the time after the inversion to the critical value of the above-described rotation current value can be used as the interval of the inversion. By determining the inversion time in this way, even if the time required to reach the fem boundary value of the above-described rotation current value is small after the inversion, the polishing rate can be made substantially fixed. Further, in this experimental example, the number of rotation revolutions, the number of revolutions, and the polishing tool 12 are set to specific values with respect to the glass substrate (the pressure of 3 and the slurry supply amount). As shown in the figure, the present invention is described. In the following, the drive control of the motor is set such that when the rotation current value is equal to or less than the TH value, the motor 74 is reversed from forward rotation to reverse rotation, and reverse rotation is reversed to forward rotation. Therefore, as shown in the graph of the figure' The rotation current value (abrasive rate) rises, and then the 'rotation current value (abrasive rate) decreases as the polishing time elapses. Moreover, if the rotation current reaches below the TH value again, the motor 74 reverses, so the rotation current value (The polishing rate) will rise again. Thus, the rotation current value has a positive (four) relationship with the polishing rate. Moreover, the threshold value of the controllable rotation current value is directly set to be '' and the motor 74 is utilized according to the threshold value. The rotation direction of the grinding tool 12 is reversed. By controlling the degree of the polishing rate shown in the figure above [S ] 148796.doc -15 - 201107077 (bar graph), the polishing rate is controlled to be substantially 岐 and controlled. Further, according to the polishing method of the embodiment, the control unit controls the motor 6〇' to reverse the revolving direction of the polishing tool 12 while the rotation direction of the polishing tool 12 is reversed. In the case of a device for rotating and revolving the polishing tool η as in the case of the polishing machine 2 of the embodiment, the torque of the rotation axis (output shaft 44: see FIG. 3) is rotated and the revolving axis (spindle 3〇: reference) Fig. 3) In terms of the balance of the rotational torque, it is preferable that the revolution direction is reversed while the rotation direction is reversed. Further, in the embodiment, the continuous polishing apparatus 10 in which a plurality of polishing machines are provided is described. However, the polishing method of the present invention may be applied to a polishing apparatus including one polishing machine 20, and Although the grinding machine 20 for rotating and revolving the polishing tool 12 has been described, the polishing method of the present invention can also be applied to a polishing apparatus in which the polishing tool 12 is only rotated. In the above embodiment, the case where the rotation direction of the polishing tool 12 and the revolution direction are reversed at a specific time point and the polishing rate of the glass substrate G is controlled to be substantially fixed is described. On the other hand, in the shaping of the polishing tool 12 that is periodically performed, the glass can be lifted by focusing on the rotation direction of the polishing tool 2 shortly after the shaping, and the rotation direction of the polishing tool 2 before the shaping is performed. The polishing rate of the substrate G. That is, the polishing method of the embodiment includes a shaping step. The so-called shaping step, as shown in Fig. 7A, refers to the step of shaping the grinding tool 12 by pressing the grinding tool 12 to the shaping member 8 and rotating the grinding tool 12 and the shaping member 80 relative to each other. Furthermore, in FIG. 7A, the member 80' is fixed relative to the fixed jaw shape 148796.doc •16·201107077 member 80', and the grinding tool 12 is rotated or self-revolved in the direction of the arrow A, but the grinding tool 12 can be fixed to make the shaping. The member 8 is rotated or self-revolving, and the grinding tool 12 and the shaping member 8 are also rotated. As the shaping member 80, a diamond grindstone configured in a disk shape or a rectangular shape can be exemplified. As shown in FIG. 7B, one example of the elevated polishing rate is the rotation direction indicated by the arrow B of the polishing tool 12 when the glass substrate G is polished after the shaping step, and is set to be relative to the shaping step shown in FIG. 7A. The direction of rotation indicated by the arrow eight is the opposite direction. The polishing tool 12 is periodically shaped by the shaping member rib during the polishing of the glass substrate G. When the glass substrate is polished after the shaping step, the rotation direction of the polishing tool 12 is set to be relative to the shaping step. The direction of rotation is in the opposite direction. As shown in Fig. 7A, at the time of shaping, the woven fabric of the polishing tool 12 has the directivity of the upstream side from the shaping direction toward the downstream side (inclination angle Θ2) by the relative rotation of the grinding tool 12 and the shaping member 80. Thereby, the polishing tool 12 is rotated in the reverse direction with respect to the inclination direction of the pile 12B generated during the shaping to polish the glass substrate G. Thereby, as shown in Fig. 7B, the pile nB is ground while the glass substrate 〇 is being subjected to a large rotational resistance. Therefore, the polishing rate of the glass substrate 上升 is increased by the rotational resistance of the pile 12B. A detailed description will be given using a diagram of FIG. 8 schematically shown. The horizontal axis t of the graph of the figure is the time axis, and the left vertical axis indicates the polishing rate (unit: μιη/min). As shown in the graph, the polishing tool 12 is rotated forward and reversed to perform polishing of the glass substrate G. At the time point (a) of the polishing step, the polishing tool 12 is shaped as shown in Fig. 7A. Thereafter, as shown in Fig. 7B, 148796.doc • 17-201107077 The direction of rotation of the polishing tool 12 is set to be in the direction of the shaping, and the polishing of the glass substrate G is continued. As shown in the chart of Figure 8, Y. The peak value of the polishing rate after the square shaping (a) is greatly increased with respect to the peak value (b) of the polishing rate by the usual positive, negative, and reverse rotation. The comparative example will be described using the graph of Fig. 9 . In this comparative example, the rotation direction of the polishing tool 12 at the time of shaping was the same as the rotation direction of the polishing tool shortly after the shaping. According to the comparative example, it is known that the shaping of the polishing tool 12 by the shaping of the time point (A) causes the peak value of the polishing rate not to increase from the value of b to (the value, the amount of rise (the value of the value - b value) is small. The amount of rise (& value - b value) of the embodiment shown in Fig. 8. Moreover, in the embodiment of Figs. 7A and 7B, the state in which the abrasive article is in the state of the new product or just after trimming is obtained. However, if the polishing tool 12 is continuously used for a long period of time, the curl of the pile 12B which is retracted by the polishing cannot be sufficiently retracted by the shaping, and the polishing rate cannot be greatly improved. That is, as shown in Fig. 10A, During the shaping, the polishing tool 12 is rotated in the direction of the arrow A. After the polishing is performed not only after the grinding, as shown in the figure, 'the polishing tool 12 is reversed in the direction of the arrow B. If the grinding is continued in this state, then As shown in Fig. 10C, the pile 12β of the polishing tool 12 is inclined in the rubbing direction, and as a result, the polishing rate is lowered. Moreover, as shown in Fig. D0D, even if shaping is performed in the direction of the arrow A thereafter, it cannot be made by Grinding and returning the curl of the fluff 12B back to Figure i〇A. Therefore, it is impossible to increase the grinding rate of the grinding which is performed shortly thereafter. In this case, the phase of the shaping member and the grinding tool 12 will be 148796.doc •18-201107077: Rotate The direction ' is set to be in the same direction as the rotation direction of the grinding tool i2 immediately before the shaping step. The woven hair i2b of the polishing tool 12 immediately before the shaping step has a characteristic of tilting toward the rotation direction of the polishing tool 12 immediately before the shaping step. When shaping the polishing tool 12, the 'relative rotation direction of the shaping member and the polishing tool 12' is set to be in the same direction as the rotation direction of the polishing tool 12 immediately before the shaping step, thereby being further enhanced during shaping. The directionality of the pile 12B of the abrasive article 12 is imparted. That is, as shown in Fig. NA, the inclination angle θι of the pile 12B can be made larger than the inclination angle center shown in Fig. M, so that, as shown in Fig. 11B, it can be stepped up. After the large shaping step, the rotation resistance of the woven fabric 12B is reversed when the polishing tool is inverted. Thus, the polishing rate of the glass substrate G can be greatly improved. Further, FIG. 11At is indicated by the arrow B. In the figure UB, the rubbing direction is indicated by an arrow A. That is, it is revealed that the shaping direction is reversed with respect to the drawings and the graphs, i〇A to 10D, and the rotation direction of the grinder 12 which is implemented shortly thereafter is reversed. An example will be specifically described using a diagram schematically shown in Fig. 12. The axis t of the graph of the S-chart is the time axis, and the left vertical axis indicates the polishing rate (unit: μιη/min). The polishing tool 12 is rotated in the reverse direction and reversed to perform the polishing of the glass substrate G, and the shaping shown in Fig. 7A is performed at the time points (A) and (B) of the polishing step. Then, at the subsequent time point ( c) After the shaping shown in Fig. 11A is carried out, as shown in Fig. iiB, 'the grinding tool 12 is reversed and the grinding is continued. By this, as shown in the graph of Fig. 12, it can be seen that the peak value (d) of the polishing rate after the shaping of the figure A is significantly higher than the value of the previous polishing rate by 148796.doc • 19-201107077 At the time points (D) and (e), the shaping system is performed along with the 1 shape, that is, the shaping shown in FIG. 11A can also be performed for each shaping, but it is preferably necessary for the interval when the material is below a certain value. Implemented at the time. The present application has been described in detail with reference to the specific embodiments of the present invention. However, it is obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. The present application is based on the application of the Japanese Patent Application No. 2009-135108, the entire contents of which are hereby incorporated by reference. [Industrial Applicability] [Brief Description of the Drawing] The object to be polished by the polishing apparatus of the plate-shaped body of the present invention is not limited to the glass substrate for FPD, and the glass for building materials or mirrors may be used. As a target, the board can also be used as a target for metal plates (four). Fig. 1 is a bird's eye view of a glass substrate polishing apparatus of an embodiment. Fig. 2 is a plan view showing the main part of the polishing apparatus shown in Fig. 1. Fig. 3 is a longitudinal sectional view showing the structure of a grinder of the polishing apparatus shown in Fig. 。. Fig. 4 is a view showing a revolution trajectory of the grinding tool of the grinder shown in Fig. 3. Fig. 5A is a view showing the rotational resistance of the polishing tool with respect to the glass substrate. Fig. 5B is a view showing the rotational resistance of the polishing tool with respect to the glass substrate. Fig. 5C is a view showing the rotational resistance of the polishing tool with respect to the glass substrate. Fig. 5D is a view showing the rotational resistance of the polishing tool with respect to the glass substrate. The graph is a graph showing the relationship between the motor's rotation current value and the polishing rate. 148796.doc -20-201107077 Fig. 7A is an explanatory view showing the relationship between the polishing tool and the shaping member in the case where the polishing rate is increased. Fig. 7B is an explanatory view showing the relationship between the polishing rate of the polishing material and the shaping member of the polishing material. Fig. 8 is a graph showing changes in the back grinding rate of the polishing tool after shaping. Fig. 9 is a graph showing a change in the polishing rate without inverting the polishing tool after shaping. Fig. 10A is a view showing the continued use of the abrasive article. Fig. 10B showing the curl of the pile when the glass substrate is polished while grinding the glass substrate, Fig. 10B shows the drawing by continuing to use the polishing tool. Fig. 10C shows the curling of the fluff which is picked up by the bow. The curl of the pile caused by the grinding of the pile caused by the abrasive tool Fig. 1 〇D shows the continued use of the 5 brothers. Example of the polishing tool and the shaping structure Fig. 11A is an explanatory view showing a red-turn relationship of the first member for increasing the polishing rate. Fig. 1B is an illustration showing the relationship of the rotation of the lift-up rate. The tool and the shape-rotation diagram of the shaping tool and the grinding tool in the shaping step are the same as the material to be shaped. The spinner of the previous abrasive tool. A chart showing the change in the grinding rate of the Ninth. [Main component symbol description] I48796.doc 201107077 10 Grinding device 12 Grinding tool 12A Grinding tool base 12B Woven hair 14 Platform 16 Cleaning device 20 Grinding machine 22 Guide block 24 Base table 28 Bracket 29 Pinion 30 Spindle 32 Bearing 34 Body bushing 36 Column 38 Hydraulic jack 40 Piston 42 Grinding head 44 Output shaft 46 Bearing 48 Gear 50 Gear 52 Shaft 54 Gear -22 148796.doc 201107077 56 Idler gear 58 Output gear 60 rpm motor 62 Motor output shaft 64 Rotary joint 66 Upper plate 70 air spring 72 universal joint 74 self-rotating motor 76 output shaft 80 shaping member 148796.doc -23-