201238712 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種玻璃板之研磨方法。 【先前技術】 利用藉由使熔融玻璃流入至熔融錫浴上而製造玻璃板之 浮式法之玻璃板之製造裝置揭示於專利文獻1、2等。又， 自先前以來亦已知有將藉由浮式法而製造之玻璃板研磨成 液晶顯示器或電漿顯示器等FPD(Flat Panel Display，平板 顯示器）用玻璃基板之研磨裝置。 以浮式法製造之玻璃板於其表面存在微小之凹凸或起伏 (3〜30 mm左右之間距、且最大高度為〇.3 μπι左右之起 伏），該種微小之凹凸或起伏成為導致圖像產生畸變或色 差之原因。因此’必需藉由研磨除去微小之凹凸或起伏。 專利文獻3中揭示之研磨裝置將保持於玻璃保持構件之 玻璃板按壓於安裝於研磨具保持壓盤之研磨具，並且使研 磨具保持壓盤及玻璃保持構件相對地移動，而除去玻璃板 之微小之凹凸或起伏。 [先前技術文獻] [專利文獻] [專利文獻1]曰本專利特開2008-239370號公報 [專利文獻2]日本專利特開2009-46366號公報 [專利文獻3] WO 2007/020859號公報 【發明内容】 [發明所欲解決之問題] 162774.doc 201238712 先前，並未充分揭示如下研磨方法：將藉由浮式法製造 之玻璃板即於表面存在微小凹凸或起伏之玻璃板研磨成作 為圖像無畸變或色差之FPD(F1 at Panel Display，平板顯示 器）用玻璃基板而最佳之玻璃板。 本發明係鑒於上述情況而完成者，其目的在於提供一種 將藉由浮式法製造之玻璃板研磨成作為FPD用玻璃基板而 最佳之玻璃板之玻璃板的研磨方法。 [解決問題之技術手段] 為達成上述目的，本發明提供一種玻璃板之研磨方法， 其將藉由使熔融玻璃流入至熔融錫浴上而製造之玻璃板、 且厚度為0.7 mm以下、1邊之長度為1〇〇〇 mm以上、楊氏 模數為65 GPa以上之玻璃板作為研磨對象之玻璃板，且 藉由玻璃保持構件保持上述玻璃板之非研磨面，且藉由 研磨具對位於該玻璃板之研磨面之高度〇·3 μιη以下之起伏 進行研磨而使之降低至〇.〇5 μηι以下，從而製造平板顯示 器用玻璃基板。 藉由浮式法製造之玻璃板、且用作FPD用玻璃基板之厚 度為0.7 mm以下、1邊之長度為1〇〇〇 mni以上、楊氏模數 為65 GPa以上之玻璃板’於其表面（研磨面）以3〜3〇爪爪左 右之間距存在最大高度為0.3 μηι左右之起伏。因此，於本 發明中，藉由研磨具對位於玻璃板之研磨面之高度〇.3 μιη 以下之起伏進行研磨，而將該起伏之最大高度降低至〇〇5 μιη以下。藉此’可製造作為不使圖像產生畸變或色差之 FPD用玻璃基板而最佳之玻璃板。 162774.doc 201238712 本發明之上述研磨具較佳為，A硬度為2〇以上、d硬度 為99以下、厚度為！ 〇〜2 5 _、厚度分佈為士⑺爪以 内。 根據本發明，可藉由如上述般規定研磨具之硬度、厚 又厚度刀佈，而將藉由浮式法製造之玻璃板研磨成作為 FpD用玻璃基板而更佳之玻璃板。 本發明之上述玻璃保持構件較佳為，壓縮率為 7〇/〇壓縮彈性模數為70〜98、A硬度為2〜20、厚度為 〇·3〜2·〇 mm、厚度分佈為士〇 〇5 mm以内。 根據本發明，可藉由如上述般規定玻璃保持構件之壓縮 率、壓縮彈性模數 '硬度、厚度 '厚度分佈，而將藉由浮 式法製造之玻璃板研磨成作為FPD用玻璃基板而更佳之玻 璃板。 本發明之上述玻璃保持構件隔著密封材料而安裝於玻璃 保持壓盤，且该玻璃保持壓盤於將評價長度設為3〇 ^⑺時 之起伏曲線之最大剖面高度較佳為2〇 μηι以下。 根據本發明，由於可藉由如上述般規定玻璃保持壓盤之 起伏曲線之最大剖面高度，而藉由玻璃保持構件良好地吸 收存在於玻璃板之非研磨面之起伏，故而可將藉由浮式法 製造之玻璃板研磨成作為FPD用玻璃基板而更佳之玻璃 板。 本發明之上述研磨具隔著密封材料而安裝於研磨具保持 壓盤，且該研磨具保持壓盤於將評價長度設為3〇 mm時之 剖面曲線之最大剖面高度較佳為丨〇〇 μηι以下。 162774.doc 201238712 根據本發明，由於可藉由如上述般規定研磨具保持壓盤 之剖面曲線之最大剖面高度，而抑制研磨具之表面之起 伏故而可將藉由洋式法製造之玻璃板研磨成作為卿用 玻璃基板而更佳之玻璃板。 本發明述研磨具以固定之負重對上述玻璃板進行按 I D玄負重之偏差較佳為平均負重之丨〇%以下。 根據本發明’可藉由如上述般規^研磨具相對於玻璃板 之負重’而將藉自浮式法製造之玻璃板研磨成作為FpD用 玻璃基板而更佳之玻璃板。 本發明之較佳為對上述研磨具進行整形時，將修整磨石 及以包圍邊修整磨石之方式配置之無研磨能力之框架按壓 在上述研磨具上以對上述研磨具進行整形。 根據本發明，藉由特定之壓力將修整磨石、及框架按壓 於研磨具而藉由修整磨石對研磨具之面進行研磨。此時， 上述壓力集中於位於修整磨石之外周之框架，但由於框架 不具有研磨能力，故而與框架接觸之研磨具之一部分之面 未經研削》即’僅藉由均勻地施加壓力之修整磨石對研磨 具之表面進行研削《藉此’由於研磨具之表面整體被研磨 得較為平坦，故而可改善修整磨石之進行整形。 [發明之效果] 根據本發明之玻璃板之研磨方法，可將藉由浮式法製造 之玻璃板研磨成作為FPD用玻璃基板而最佳之玻璃板。 【實施方式】 以下，根據隨附圖式詳細說明本發明之玻璃板之研磨方 162774.doc 201238712 法之較佳實施形態。 圖1係表示應用本發明之實施形態之玻璃板之研磨方法 之研磨裝置10之整體構成的立體圖。圖2係圖1所示之研磨 裝置10之側視圖。 該等圖所示之研磨裝置10為如下研磨裝置，即，使用研 磨具將藉由浮式法製造之玻璃板、且例如厚度為0 7 mm以 下、1邊之長度為1000 mm以上、楊氏模數為65 GPa以上之 玻螭板G之表面（研磨面）研磨成FPD用玻璃基板所需要之平 坦度。即，該研磨裝置10為如下裝置：對以3〜3〇 mm左右 之間距存在最大高度為〇3 μιη左右之起伏之玻璃板G之研 磨面進行研磨，而將其起伏之最大高度降低至〇〇5 pm以 下藉此’製造作為不使圖像產生畸變或色差之jrpD用玻 璃基板而最佳之玻璃板。 再者’上述起伏之測定方法為爪b〇〇31 ·· 1982與JIS B0601 . 1982中記載之方法。又，用以使上述起伏成為 〇·〇5 μηι以下之研磨量根據研磨具之硬度而決定。研磨具 之硬度越高，越能以較少之研磨量減少起伏。 研磨裝置ίο包含研磨頭12與壓盤14。研磨頭12包含··玻 璃保持構件16,其保持玻璃板G之非研磨面；玻璃保持壓 盤20，其隔著密封材料18而安裝有玻璃保持構件16 ;及布 材22，其安裝有玻璃保持壓盤2〇。於布材。固定有旋轉軸 24 ’且藉由旋轉轴24以其軸訊為中心進行旋轉而使研磨 頭12旋轉，並且藉由旋轉軸24以公轉轴&為中心進行公轉 而使研磨頭12公轉。 162774.doc 201238712 又，經由中空之旋轉轴24對布材22之空氣室23供給壓縮 空氣，該壓縮空氣之壓力隔著玻璃保持壓盤20、密封材料 18、及玻璃保持構件16而傳遞至玻璃板G。 上述壓盤14包含研磨具26、及隔著密封材料28安褒研磨 具26之研磨具保持壓盤30〇密封材料28為軟質且提高吸附 保持性之樹脂製（例如，聚胺基曱酸酯製）之密封材料。 因此’本實施形態之研磨裝置10藉由上述壓縮空氣之塵 力而將玻璃板G之研磨面按壓於研磨具26，且使研磨頭12 自轉、公轉，藉此研磨玻璃板G之研磨面。 研磨具26較佳為A硬度（依據ISO 7619: 1997)為20以 上、D硬度（依據iso 7619)為99以下、厚度為i.o〜2.5 mm、 厚度分佈為士0.05 mm以内。 若研磨具26之A硬度未達20，則無法降低玻璃板G之起 伏’若研磨具26之D硬度超過99，則玻璃板G易於斷裂。 又，若研磨具26之厚度未達ίο mm，則無法對研磨具26加 工溝槽。尤其若於大面積之研磨具26中無法加工溝槽，則 有研磨粒分佈不均勻而於玻璃板G之加工中產生問題之 虞。相對於此，若研磨具26之厚度超過2.5 mm，則有研磨 具26之變形量變大而降低玻璃板〇之加工品質之虞。再 者’研磨具26之厚度分佈為除溝槽加工部分以外之區域之 (最大厚度）-(最小厚度）。若該厚度分佈超過±〇 〇5 ，則 有壓力分佈變大而降低玻璃板之加工品質之虞。 如此，可藉由如上述般規定研磨具26之硬度、厚度、厚 度为佈’而將藉由浮式法製造之玻璃板G研磨成更適合作 162774.doc 201238712 為fpd用玻璃基板之玻璃板。 另一方面，本案發明者經銳意研究之結果發現：為使研 磨後之玻璃板之起伏成為0 05 μηι以下，除如上述般管理 . 研磨具26之Α硬度以外，進而管理玻璃保持構件16之壓縮 率、壓縮彈性模數、Λ硬度、厚度、及分佈則更為有效。 例如’若玻璃保持構件1 6之Α硬度過低，則玻璃保持構 件16之耐久性降低，而無法反覆使用玻璃保持構件16。 又，於玻璃保持構件16之A硬度適度低之情形時，由於玻 璃保持構件16吸收存在於玻璃板G之非研磨面之起伏，故 而可藉由研磨具26良好地對存在於玻璃板G之研磨面之起 伏進行研磨。相對於此，若玻璃保持構件16之八硬度過 冋，則於存在於玻璃板G之非研磨面之起伏無法由玻璃保 持構件16吸收之狀態下，以玻璃保持構件16保持玻璃板 G ’且藉由研磨具26研磨玻璃板g之研磨面。因此，於自 玻璃保持構件16卸除玻璃板g時，玻璃板g產生回彈，其 結果，有時會於玻璃板G之研磨面殘留有超過〇 〇5 之起 伏。 又，若玻璃保持構件16之厚度分佈大於±〇〇5 mm，則有 時會產生玻璃保持構件16之緩衝性於玻璃板G之面内產生 • 偏差，從而導致起伏未均勻地消失之問題。 為解決上述問題，玻璃保持構件16較佳為，壓縮率（依 據JIS L1021-6 : 2007附錄1)為10〜7〇%、壓縮彈性模數（依 據JIS L1021-6 : 2007附錄1，其中，初始負重設為1〇〇 gf/cm2，最終負重為112〇成咖2)為7〇〜98 ' α硬度為 162774.doc 201238712 2〜20,厚度為（^〜以職、厚度分佈為过“喊内。 /縮率係表示追隨初始之破璃板G之緩衝性，壓縮彈性 模數為表示反覆使用之情形之恢復之程度之參數。 再者’於本實施之形態中，賴㈣構件16較佳為發泡 聚胺基甲酸醋製，可適當選擇使用通常所使用之材質者。 又，玻璃保持構件16之管理係當玻璃板G變薄時尤其需 要縮小管理範圍。例如，板厚G5随以下之玻璃板G之情 形之玻璃保持構件16較佳為壓縮率為1〇〜7〇%、壓縮彈性 模數為70〜98、A硬度為2〜20、厚度為(^〜丨5 mm、厚度分 佈為±0.05 mm以内。又，板厚〇3 mm以下之玻璃板= 形之玻璃保持構件16較佳為壓縮率為1〇〜7〇%、壓縮彈性 模數為70〜98、A硬度為2〜20、厚度為ο.'!.2 mm、厚度分 佈為±0.05 mm以内。 可藉由如上述般規定玻璃保持構件丨6之壓縮率、壓縮彈 性模數、A硬度、厚度、厚度分佈，而將藉由浮式法製造 之玻璃板G研磨成作為FPD用玻璃基板而更佳之玻璃板。 另一方面’於即便管理玻璃保持構件16，玻璃保持壓盤 20之起伏曲線之最大剖面高度亦過高之情形時，判明存在 如下之情形：無法藉由玻璃保持構件丨6良好地吸收存在於 玻璃板G之非研磨面之起伏’從而無法將玻璃板G之研磨 面之起伏研磨為0.05 μιη以下。 為解決上述問題，對於隔著密封材料1 8而安裝有玻璃保 持構件16之玻璃保持壓盤20之面而言，將評價長度設為3〇 mm時之起伏曲線之最大剖面高度較佳為2〇 μιη以下。 162774.doc 201238712 由於可藉由如上述般規定玻璃保持壓盤20之起伏曲線之 最大剖面高度，而藉由玻璃保持構件16良好地吸收存在於 玻璃板G之非研磨面之起伏，故而可將藉由浮式法製造之 玻璃板研磨成作為FPD用玻璃基板而更佳之玻璃板。 又，於即便管理研磨具26，研磨具保持壓盤3〇之剖面曲 線之最大剖面尚度亦過尚之情形時，判明於研磨具2 6之表 面產生較大之起伏，從而無法將玻璃板〇之研磨面之起伏 研磨為0.05 μηι以下。 為解決上述問題，對於隔著密封材料28而安裝有研磨具 26之研磨具保持壓盤3〇之面而言，將評價長度設為3〇 時之剖面曲線之最大剖面高度較佳為1〇〇 μηι以下。 由於可藉由如上述般規定研磨具保持壓盤30之剖面曲線 之最大剖面尚度，而抑制研磨具26之表面之起伏，故而可 將藉由浮式法製造之玻璃板研磨成作為FPD用玻璃基板而 更佳之玻璃板。 再者’起伏曲線之最大剖面高度記載於jIS β〇6〇ι : 2001。起伏曲線之最大剖面高度係於測定長度3〇爪爪、 XC=0.8 mm之測定條件下且以東京精密股份公司製造之 Surfcom「1400-D64」進行測定。 進而’使玻璃板G之研磨面對研磨具26按壓之負重之偏 差較佳為平均負重之1 〇%以下。 可藉由如上述般規定研磨具26對玻璃板G之負重，而將 藉由浮式法製造之玻璃板G研磨成作為FPD用玻璃基板而 更佳之玻璃板。再者，作為負重分佈之測定裝置，可使用 162774.doc 201238712 nitta股份公司製造之大面積壓力分佈測定系統之「BIG_ MAT」或「HUGE-MAT」。 如以上所述，根據本實施形態之研磨裝置丨〇，將藉由浮 式法製造之玻璃板G、且厚度為0.7 mm以下、1邊之長度為 1000 mm以上、楊氏模數為65 GPa以上之玻璃板G作為研 磨對象’藉由玻璃保持構件16保持玻璃板g之非研磨面， 藉由利用研磨具26對位於玻璃板G之研磨面之高度〇 3 μπι 以下之起伏進行研磨而使之降低至0.05 μιη以下從而製造 平板顯示器用玻璃基板。藉此’可製造作為位於研磨面之 起伏之最大高度為〇.〇5 μπι以下、且不使圖像產生畸變或 色差之FPD用玻璃基板而最佳之玻璃板〇。 於下述中表示研磨規格之一例。 研磨壓力：2 kPa〜25 kPa 研磨毁料：自研磨具保持壓盤之漿料供給孔供給氧化飾 水溶液 研磨具.軟質胺基曱酸酯製絨面革狀且於表面具有使聚 料流動之溝槽（溝槽間距4 5 mm、溝槽寬度15 mm、溝槽 深度1〜1 _5 mm) 玻璃板之厚度：0.2 mm〜0.7 mm 玻璃板之形狀：1邊超過1000 mm之矩形狀玻璃板 玻璃板之非研磨面：以玻璃保持構件密接保持 以上為研磨規格之一例。 然而’於本實施形態之研磨裝置1〇中，為維持玻璃板G 之研磨率’而藉由含有鑽石研磨粒之修整磨石定期地對研 162774.doc •12- 201238712 磨具26之表面進行研削而實施進行整形。 先刖，如圖3之模式圖所示，將與玻璃板G大致相同尺寸 且板狀之修整磨石40安裝於玻璃保持構件16。然後，藉由 供給至圖1所示之布材22之空氣室23之壓縮空氣的氣壓而 將圖3之修整磨石40按壓於研磨具26，對研磨具26之面進 行研削。此時’與玻璃板G之研磨同樣地，修整磨石4〇一 面藉由研磨頭12之動作進行自轉、公轉一面對研磨具％之 面進行研削。 於先前之修整磨石40之研磨時，產生上述氣壓集中於修 整磨石4〇之邊緣部分4〇A之現象。因此，由於與邊緣部分 40A接觸之研磨具26之表面之一部分26A被研磨得較其他 部分26B多，故而存在研磨具26之表面整體被研磨得不平 坦之不良情況。又，與邊緣部分4〇a接觸之上述一部分表 面26 A藉由修整磨石40之自轉、公轉，而如圖4之平面圖所 示般於研磨具26之表面呈現為環狀。 為防止該種不良情況’於本實施形態之研磨裝置丨〇中’ 於進行整形時，如圖5所示，將不具有鑽石研磨粒而無研 磨旎力之矩形狀之框架42如圖6之平面圖所示般以包圍修 整磨石40之方式安裝於玻璃保持構件16。然後，藉由供給 至布材22之空氣室23之壓縮空氣之氣壓而將修整磨石4〇、 及框架42按壓於研磨具26，藉由修整磨石4〇對研磨具26之 表面進行研削（進行整形）。 此時’上述氣壓集中於位於修整磨石4〇之外周之框架 42 ’但由於框架42不具有研磨能力，故而研磨具26之與框 162774.doc 13 201238712 架42接觸之部分未被研削。即，僅藉由均勻地施加氣壓之 修整磨石40對研磨具26之表面進行研削。藉此，由於研磨 具26之面整體被研削得較為平坦，故而可改善利用修整磨 石40之進行整形。 再者，不僅於研磨具26之修整時使用框架42，較佳於玻 璃板G之研磨時亦使用框架42 ^藉此，可防止於玻璃板g 之研磨時氣壓集中於玻璃板G之邊緣，故而可防止玻璃板 G之邊緣之研削過多。作為框架42之材質，可例示不鏽 鋼、鐵、鋁、聚乙烯、聚胺基甲酸酯等不具有研磨能力之 材質》 又，於實施形態之研磨裝置10中，為維持玻璃板G之研 磨率而實施藉由定期地對研磨具26之表面進行水清洗而 除去附著於研磨具26表面之研磨液中之氧化鈽等殘渣之修 整。 先前之水清洗裝置於研磨具26之上方配置有使喷射孔朝 向下側之打磨用水噴嘴。自該水噴嘴之上述噴射孔向與研 磨具26之表面正交之方向喷射清洗水，並且使研磨具％及 水噴嘴於水平方向相對地移動而實施研磨具26之修整。 然而，於先前之清洗裝置中，有無法效率良好地除去附 著於研磨具26之表面之上述殘渣，且，無法將除去之殘渣 效率良好地沖洗至研磨具26之系統外之不良情況。 為防止該種不良情況’於本實施形態之研磨裝置丨〇中， 如圖7之側視圖所示般使打磨用水喷嘴44傾斜，將自喷射 孔46喷射之清洗水48之噴射角度Θ設定為銳角。而且，藉 162774.doc 14 201238712 由使水喷嘴44與研磨具26於水平方向相對地往復移動，而 除去附著於研磨具26之表面之殘渣》 藉此，附著於研磨具26表面之殘渣因傾斜喷射之清洗水 48之壓力而翻出，故而效率良好地被除去。又，除去之殘 渣藉由傾斜喷射之清洗水48而被效率良好地沖洗至研磨具 26之系統外。藉此’可改善藉由水喷嘴44而進行之修整。 再者，就殘渣之翻出效率、及殘渣之洗除效率之觀點而 言，清洗水48之噴射角度θ較佳為1〇〜45度，更佳為3〇度。 又，清洗水48衝撞研磨具26時之衝擊力會有若弱則殘渣之 除去效率降低而若高則會導致研磨具26破損之虞，故較佳 為5〜50 kPa。進而，研磨具26與水喷嘴44之相對速度若較 慢則研磨具26之打磨效率降低，而若較快則殘渣之除去效 率降低’故較佳為3〜20 m/min。 已參照詳細且特定之實施形態對本發明進行了說明但 熟悉此技藝者將可了解可於不脫離本發明之精神與範圍之 情況下加入各種變更或修正。 本申請案係基於201!年3月i曰提出申請之曰本專利申請 案201 1-044250者，其内容以參考之形式併入本文中。 【圖式簡單說明】 圖1係表示應用本發明之實施形態之研磨具之研磨裝置 之整體結構的立體圖。 圖2係圖1所示之研磨裝置之側視圖。 圖3係表示先前之修整磨石之研磨具之進行整形方法之 模式圖^ I62774.doc '15- 201238712 圖4係藉由圖3所示之進行整形方法進行整形之研磨具之 平面圖。 圖5係表示本發明之實施形態之修整磨石之研磨方法之 模式圖。 圖6係藉由圖5所示之進行整形方法進行整形之研磨具之 平面圖。 圖7係表示打磨用水噴嘴之研磨具之修整方法之側視 圖。 【主要元件符號說明】 10 研磨裝置 12 研磨頭 14 壓盤 16 玻璃保持構件 18 密封材料 20 玻璃保持壓盤 22 布材 23 空氣室 24 旋轉轴 26 研磨具 28 在、封材料 30 研磨具保持壓盤 40 修整磨石 42 框架 44 水喷嘴 162774.doc ' 16 - 201238712 46 喷射孔 48 清洗水 Pi 軸芯 P2 公轉軸 G 玻璃板 162774.doc . 17-201238712 VI. Description of the Invention: [Technical Field to Which the Invention Is Ascribed] The present invention relates to a method of polishing a glass plate. [Prior Art] A manufacturing apparatus for a glass plate in which a glass plate is produced by flowing molten glass into a molten tin bath is disclosed in Patent Documents 1, 2 and the like. Further, a polishing apparatus for polishing a glass plate manufactured by a floating method into a glass substrate for an FPD (Flat Panel Display) such as a liquid crystal display or a plasma display has been known. The glass plate manufactured by the floating method has minute irregularities or undulations on its surface (a distance of about 3 to 30 mm and a maximum height of about 3.3 μπι), and the slight unevenness or undulation becomes an image. The cause of distortion or chromatic aberration. Therefore, it is necessary to remove minute irregularities or undulations by grinding. The polishing apparatus disclosed in Patent Document 3 presses the glass plate held by the glass holding member against the polishing tool attached to the polishing tool holding platen, and moves the polishing tool to hold the platen and the glass holding member relatively, thereby removing the glass plate. Tiny bumps or undulations. [Patent Document 1] [Patent Document 1] Japanese Laid-Open Patent Publication No. 2008-239370 (Patent Document 2) Japanese Patent Laid-Open Publication No. 2009-46366 (Patent Document 3) WO 2007/020859 SUMMARY OF THE INVENTION [Problems to be Solved by the Invention] 162774.doc 201238712 Previously, the following polishing method has not been fully disclosed: a glass plate manufactured by a floating method, that is, a glass plate having fine irregularities or undulations on its surface is ground as a figure. A glass plate that is optimal for a FPD (F1 at Panel Display) without distortion or chromatic aberration. The present invention has been made in view of the above circumstances, and an object thereof is to provide a polishing method for polishing a glass plate produced by a floating method into a glass plate which is optimal as a glass substrate for FPD. [Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for polishing a glass sheet which is produced by flowing molten glass into a molten tin bath and having a thickness of 0.7 mm or less and one side. A glass plate having a length of 1 mm or more and a Young's modulus of 65 GPa or more is used as a glass plate to be polished, and the non-abrasive surface of the glass plate is held by a glass holding member, and is positioned by a polishing tool The glass substrate for a flat panel display was produced by polishing the embossed surface of the glass plate at a height of 〇·3 μm or less and lowering it to less than 〇5 μηι. a glass plate produced by a floating method and used as a glass plate for FPD having a thickness of 0.7 mm or less, a length of one side of 1 〇〇〇mni or more, and a Young's modulus of 65 GPa or more The surface (grinding surface) has a maximum height of about 0.3 μm around a distance of 3 to 3 〇 claws. Therefore, in the present invention, the undulation of the polishing surface of the glass sheet at a height of 〇.3 μm or less is ground by the polishing tool, and the maximum height of the undulation is reduced to 〇〇5 μm or less. By this, it is possible to manufacture a glass plate which is optimal as a glass substrate for FPD which does not cause distortion or chromatic aberration of an image. 162774.doc 201238712 The above-mentioned polishing tool of the present invention preferably has an A hardness of 2 Å or more, a d hardness of 99 or less, and a thickness of ! 〇~2 5 _, thickness distribution is within (7) claws. According to the present invention, the glass plate produced by the floating method can be polished into a glass plate which is more preferable as a glass substrate for FpD by specifying the hardness of the polishing tool and the thickness of the knives as described above. Preferably, the glass holding member of the present invention has a compression ratio of 7 〇/〇, a compression modulus of 70 to 98, an A hardness of 2 to 20, a thickness of 〇·3 to 2·〇mm, and a thickness distribution of gentry. 〇5 mm or less. According to the present invention, the glass plate produced by the floating method can be ground into a glass substrate for FPD by setting the compression ratio, the compression elastic modulus 'hardness, and the thickness' thickness distribution of the glass holding member as described above. Good glass plate. The glass holding member of the present invention is attached to the glass holding platen via a sealing material, and the maximum thickness of the undulation curve of the glass holding platen when the evaluation length is 3〇^(7) is preferably 2〇μηι or less. . According to the present invention, since the maximum cross-sectional height of the undulation curve of the glass holding platen can be specified as described above, the glass holding member can well absorb the undulations existing on the non-abrasive surface of the glass sheet, so that it can be floated The glass plate produced by the method is ground into a glass plate which is more preferable as a glass substrate for FPD. The above-mentioned polishing tool of the present invention is attached to the polishing tool holding platen via a sealing material, and the maximum profile height of the profile curve when the platen maintains the platen at an evaluation length of 3 mm is preferably 丨〇〇μηι the following. According to the present invention, the glass plate manufactured by the foreign method can be ground by suppressing the undulation of the surface of the polishing tool by setting the maximum profile height of the profile of the platen by the polishing tool as described above. A glass plate which is more preferable as a glass substrate for ging. The deviation of the glass plate by the Id weight load of the polishing tool according to the present invention is preferably less than or equal to 平均% of the average load. According to the present invention, the glass plate manufactured by the floating method can be ground into a glass plate which is more preferable as the glass substrate for FpD by the above-described grinding weight of the polishing tool with respect to the glass sheet. Preferably, in the present invention, when the polishing tool is shaped, the grinding stone and the frame having no grinding ability disposed so as to surround the edge grinding stone are pressed against the polishing tool to shape the polishing tool. According to the present invention, the surface of the abrasive article is ground by dressing the grindstone by pressing the dressing stone and the frame against the abrasive tool by a specific pressure. At this time, the above-mentioned pressure is concentrated on the frame located outside the dressing stone, but since the frame does not have the grinding ability, the surface of one portion of the grinding tool that is in contact with the frame is not ground, that is, 'repairing only by uniformly applying pressure. The grinding stone grinds the surface of the grinding tool. Therefore, since the entire surface of the polishing tool is ground flat, the shaping of the grinding stone can be improved. [Effects of the Invention] According to the method for polishing a glass sheet of the present invention, the glass sheet produced by the floating method can be polished into a glass sheet which is optimal as a glass substrate for FPD. [Embodiment] Hereinafter, a preferred embodiment of the polishing method of the glass plate of the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 is a perspective view showing the overall configuration of a polishing apparatus 10 to which a method for polishing a glass sheet according to an embodiment of the present invention is applied. Figure 2 is a side elevational view of the polishing apparatus 10 of Figure 1. The polishing apparatus 10 shown in the figures is a polishing apparatus which uses a polishing tool to produce a glass plate by a floating method, for example, having a thickness of 0.7 mm or less, a length of one side of 1000 mm or more, and Young's The surface (grinding surface) of the glass plate G having a modulus of 65 GPa or more is polished to the flatness required for the glass substrate for FPD. That is, the polishing apparatus 10 is a device that grinds the polished surface of the glass sheet G having a maximum height of about 3 μm around a distance of about 3 to 3 mm, and reduces the maximum height of the undulation to 〇. 〇5 pm or less is used to manufacture a glass plate which is optimal as a glass substrate for jrpD which does not cause distortion or chromatic aberration of an image. Further, the measurement method of the above-mentioned undulation is the method described in Claw b〇〇31··1982 and JIS B0601. Further, the amount of polishing for causing the undulation to be 〇·〇 5 μηι or less is determined according to the hardness of the polishing tool. The higher the hardness of the abrasive tool, the less the fluctuation can be reduced with less grinding. The grinding device ίο includes a polishing head 12 and a platen 14. The polishing head 12 includes a glass holding member 16 that holds a non-polishing surface of the glass sheet G, a glass holding platen 20 that is attached with a glass holding member 16 via a sealing material 18, and a cloth member 22 that is mounted with glass. Keep the platen 2 〇. In the cloth. The rotating shaft 24' is fixed, and the grinding head 12 is rotated about the axis of rotation by the rotating shaft 24, and the grinding head 12 is revolved by the rotating shaft 24 to revolve around the revolving shaft & 162774.doc 201238712 Further, compressed air is supplied to the air chamber 23 of the cloth 22 via the hollow rotating shaft 24, and the pressure of the compressed air is transmitted to the glass via the glass holding platen 20, the sealing material 18, and the glass holding member 16. Board G. The pressure plate 14 includes a polishing tool 26 and a polishing tool holding the pressure plate 30 via the sealing material 28 and the sealing material 28 is made of a resin which is soft and has improved adsorption retention (for example, polyamino phthalate). Sealing material. Therefore, the polishing apparatus 10 of the present embodiment presses the polishing surface of the glass sheet G against the polishing tool 26 by the dust of the compressed air, and rotates and revolves the polishing head 12, thereby polishing the polishing surface of the glass sheet G. The abrasive article 26 preferably has an A hardness (according to ISO 7619: 1997) of 20 or more, a D hardness (according to iso 7619) of 99 or less, a thickness of i.o. to 2.5 mm, and a thickness distribution of ±0.05 mm. If the A hardness of the polishing tool 26 is less than 20, the undulation of the glass sheet G cannot be lowered. If the D hardness of the polishing tool 26 exceeds 99, the glass sheet G is liable to be broken. Further, if the thickness of the polishing tool 26 is less than ίο mm, the polishing tool 26 cannot be grooved. In particular, if the groove cannot be processed in the large-area polishing tool 26, uneven distribution of the abrasive grains may cause problems in the processing of the glass sheet G. On the other hand, when the thickness of the polishing tool 26 exceeds 2.5 mm, the amount of deformation of the polishing tool 26 becomes large, and the processing quality of the glass sheet is lowered. Further, the thickness distribution of the abrasive article 26 is the (maximum thickness) - (minimum thickness) of the region other than the grooved portion. If the thickness distribution exceeds ±〇5, the pressure distribution becomes large and the processing quality of the glass sheet is lowered. Thus, the glass plate G produced by the floating method can be ground to a glass plate G which is more suitable for use as a glass substrate for fpd by arranging the hardness, thickness, and thickness of the polishing tool 26 as described above. . On the other hand, as a result of intensive research, the inventors of the present invention found that the glass holding member 16 is managed in addition to the hardness of the polishing tool 26 in order to make the undulation of the glass plate after the grinding to be 0 μm μm or less. Compression ratio, compression modulus, Λ hardness, thickness, and distribution are more effective. For example, if the hardness of the glass holding member 16 is too low, the durability of the glass holding member 16 is lowered, and the glass holding member 16 cannot be used repeatedly. Further, when the A hardness of the glass holding member 16 is moderately low, since the glass holding member 16 absorbs the undulations existing on the non-polishing surface of the glass sheet G, the polishing tool 26 can be satisfactorily present on the glass sheet G. The grinding surface is undulated for grinding. On the other hand, when the hardness of the glass holding member 16 is too high, the glass holding member 16 holds the glass sheet G' in a state where the undulation of the non-polishing surface of the glass sheet G cannot be absorbed by the glass holding member 16. The polished surface of the glass plate g is ground by the polishing tool 26. Therefore, when the glass sheet g is removed from the glass holding member 16, the glass sheet g is rebounded, and as a result, the undulations exceeding the 〇5 may remain on the polished surface of the glass sheet G. Further, when the thickness distribution of the glass holding member 16 is larger than ± 〇〇 5 mm, there is a case in which the cushioning property of the glass holding member 16 causes a deviation in the surface of the glass sheet G, and the undulation does not uniformly disappear. In order to solve the above problem, the glass holding member 16 preferably has a compression ratio (according to JIS L1021-6: 2007 Appendix 1) of 10 to 7 %, and a compression elastic modulus (according to JIS L1021-6: 2007 Appendix 1, wherein The initial load is set to 1〇〇gf/cm2, and the final load is 112〇 into 2) 7〇~98' α hardness is 162774.doc 201238712 2~20, thickness is (^~ job, thickness distribution is too) The shuffling rate indicates that the cushioning property of the original glass slab G is followed, and the compressive elastic modulus is a parameter indicating the degree of recovery of the case of repeated use. Further, in the form of the present embodiment, the slab (four) member 16 It is preferably made of a foamed polyurethane vinegar, and a material which is usually used can be appropriately selected and used. Further, the management of the glass holding member 16 is particularly required to narrow the management range when the glass sheet G is thinned. For example, the thickness G5 The glass holding member 16 in the case of the following glass sheet G preferably has a compression ratio of 1 〇 to 7 〇 %, a compression elastic modulus of 70 to 98, an A hardness of 2 to 20, and a thickness of (^ 丨 5 mm). The thickness distribution is within ±0.05 mm. Also, the glass plate with a thickness less than 3 mm = shape glass protection The holding member 16 preferably has a compression ratio of 1 〇 to 7 〇 %, a compression elastic modulus of 70 to 98, an A hardness of 2 to 20, a thickness of ο. '!. 2 mm, and a thickness distribution of ± 0.05 mm or less. The glass plate G produced by the floating method can be ground into a glass substrate for FPD by setting the compression ratio, the compression elastic modulus, the A hardness, the thickness, and the thickness distribution of the glass holding member 6 as described above. On the other hand, when the maximum cross-sectional height of the undulating curve of the glass holding platen 20 is too high even if the glass holding member 16 is managed, it is found that the glass holding member 丨6 cannot be good. The undulation of the non-polishing surface of the glass sheet G is absorbed so that the undulation of the polished surface of the glass sheet G cannot be ground to 0.05 μm or less. To solve the above problem, the glass holding member 16 is attached to the sealing material 18 via the sealing material 18. In the case where the glass is held on the surface of the platen 20, the maximum profile height of the undulation curve when the evaluation length is set to 3 mm is preferably 2 μm or less. 162774.doc 201238712 Since the glass holding pressure can be specified as described above The maximum cross-sectional height of the undulating curve of the disk 20, and the glass holding member 16 well absorbs the undulations existing on the non-polishing surface of the glass sheet G, so that the glass plate manufactured by the floating method can be ground into glass for FPD. Further, the glass plate is better than the substrate. Moreover, even if the polishing tool 26 is managed and the maximum profile of the profile of the platen 3 is maintained, the surface of the polishing tool 26 is largely undulated. Therefore, the undulation of the polished surface of the glass plate cannot be ground to 0.05 μm or less. In order to solve the above problem, in the case where the polishing tool to which the polishing tool 26 is attached via the sealing material 28 holds the pressure plate 3, the maximum profile height of the profile curve when the evaluation length is 3 较佳 is preferably 1〇. 〇μηι below. Since the maximum profile of the profile of the platen 30 can be maintained by the polishing tool as described above, the undulation of the surface of the polishing tool 26 can be suppressed, so that the glass plate manufactured by the floating method can be ground to be used as an FPD. A glass plate and a better glass plate. Furthermore, the maximum profile height of the 'undulation curve' is described in jIS β〇6〇ι: 2001. The maximum profile height of the undulation curve was measured under the measurement conditions of the measurement length of 3 〇 claws and XC = 0.8 mm, and was measured by Surfcom "1400-D64" manufactured by Tokyo Precision Co., Ltd. Further, the deviation of the weight of the glass sheet G to the pressing force of the polishing tool 26 is preferably 1% or less of the average weight. The glass plate G produced by the floating method can be ground into a glass plate which is more preferable as a glass substrate for FPD by setting the weight of the polishing tool 26 to the glass plate G as described above. Further, as the measuring device for the load distribution, "BIG_MAT" or "HUGE-MAT" of the large-area pressure distribution measuring system manufactured by 162774.doc 201238712 nitta Co., Ltd. can be used. As described above, according to the polishing apparatus of the present embodiment, the glass sheet G produced by the floating method has a thickness of 0.7 mm or less, a length of one side of 1000 mm or more, and a Young's modulus of 65 GPa. The glass plate G described above is used as a polishing target. The glass holding member 16 holds the non-polishing surface of the glass plate g, and the burrs of the polishing surface of the glass plate G having a height of 〇3 μm or less are polished by the polishing tool 26. The glass substrate for a flat panel display is manufactured by lowering it to 0.05 μm or less. By this, it is possible to manufacture a glass plate which is the best for the FPD glass substrate which has a maximum height of undulations of the polishing surface of 〇. 5 μm or less and which does not cause distortion or chromatic aberration of the image. An example of the polishing specifications is shown below. Grinding pressure: 2 kPa~25 kPa Grinding and damaging: The slurry supply hole for holding the platen from the grinding tool is supplied to the oxidized aqueous solution grinding tool. The soft amine phthalate is sueded and has a flow on the surface. Groove (trench spacing 4 5 mm, groove width 15 mm, groove depth 1~1 _5 mm) Thickness of glass plate: 0.2 mm~0.7 mm Shape of glass plate: Rectangular glass plate with 1 side exceeding 1000 mm Non-abrasive surface of the glass plate: An example in which the glass holding member is closely adhered to the above-mentioned polishing specifications. However, in the polishing apparatus 1 of the present embodiment, in order to maintain the polishing rate of the glass sheet G, the surface of the grindstone 26 of the 162774.doc • 12-201238712 is periodically performed by a dressing grindstone containing diamond abrasive grains. Grinding is carried out to perform shaping. First, as shown in the schematic view of Fig. 3, a plate-shaped dressing stone 40 having substantially the same size as the glass plate G is attached to the glass holding member 16. Then, the dressing stone 40 of Fig. 3 is pressed against the polishing tool 26 by the air pressure of the compressed air supplied to the air chamber 23 of the cloth member 22 shown in Fig. 1, and the surface of the polishing tool 26 is ground. At this time, in the same manner as the polishing of the glass sheet G, the surface of the grinding stone 4 is rotated by the operation of the polishing head 12, and the surface of the grinding tool is ground. At the time of the grinding of the conventional dressing stone 40, the above-mentioned air pressure is concentrated on the edge portion 4〇A of the dressing stone. Therefore, since one surface 26A of the surface of the polishing tool 26 which is in contact with the edge portion 40A is polished more than the other portions 26B, there is a problem that the entire surface of the polishing tool 26 is unevenly ground. Further, the portion of the surface 26A which is in contact with the edge portion 4A is rotated by the dressing of the grindstone 40, and the surface of the grindstone 26 is annular as shown in the plan view of Fig. 4. In order to prevent such a problem, in the polishing apparatus of the present embodiment, when the shaping is performed, as shown in FIG. 5, a rectangular frame 42 having no abrasive grains and no grinding force is used as shown in FIG. The glass holding member 16 is attached to the dressing stone 40 as shown in plan view. Then, the dressing stone 4〇 and the frame 42 are pressed against the grinding tool 26 by the air pressure of the compressed air supplied to the air chamber 23 of the cloth material 22, and the surface of the grinding tool 26 is ground by dressing the grindstone 4 (for shaping). At this time, the above air pressure is concentrated on the frame 42' which is located outside the dressing stone 4, but since the frame 42 does not have the grinding ability, the portion of the grinding tool 26 which is in contact with the frame 162774.doc 13 201238712 is not ground. That is, the surface of the polishing tool 26 is ground only by the dressing grindstone 40 which uniformly applies the air pressure. Thereby, since the entire surface of the polishing tool 26 is flattened, the shaping by the dressing stone 40 can be improved. Furthermore, not only the frame 42 is used for the dressing of the polishing tool 26, but also the frame 42 is preferably used for the polishing of the glass plate G. This prevents the air pressure from being concentrated on the edge of the glass plate G during the grinding of the glass plate g. Therefore, the edge of the glass sheet G can be prevented from being excessively ground. The material of the frame 42 is exemplified by a material having no polishing ability such as stainless steel, iron, aluminum, polyethylene, or polyurethane. Further, in the polishing apparatus 10 of the embodiment, in order to maintain the polishing rate of the glass sheet G On the other hand, the surface of the polishing tool 26 is periodically washed with water to remove the residue such as ruthenium oxide adhered to the polishing liquid adhering to the surface of the polishing tool 26. The prior water washing device is disposed above the grinding tool 26 with a watering nozzle for making the injection hole toward the lower side. The cleaning water is sprayed from the injection hole of the water nozzle in a direction orthogonal to the surface of the grinding tool 26, and the polishing tool 26 and the water nozzle are relatively moved in the horizontal direction to perform trimming of the polishing tool 26. However, in the conventional cleaning apparatus, the residue adhering to the surface of the polishing tool 26 cannot be efficiently removed, and the removed residue cannot be efficiently flushed out of the system of the polishing tool 26. In order to prevent such a problem, in the polishing apparatus according to the present embodiment, the polishing water nozzle 44 is inclined as shown in the side view of FIG. 7, and the injection angle Θ of the cleaning water 48 sprayed from the injection hole 46 is set to Sharp angle. Further, by 162774.doc 14 201238712, the water nozzle 44 and the polishing tool 26 are reciprocally moved in the horizontal direction to remove the residue adhering to the surface of the polishing tool 26, whereby the residue adhering to the surface of the polishing tool 26 is inclined. The pressure of the jetted washing water 48 is turned out, so that it is removed efficiently. Further, the removed residue is efficiently flushed out of the system of the polishing tool 26 by the obliquely sprayed cleaning water 48. Thereby, the trimming by the water nozzle 44 can be improved. Further, the injection angle θ of the washing water 48 is preferably from 1 〇 to 45 °, more preferably 3 Torr, from the viewpoint of the efflux efficiency of the residue and the washing efficiency of the residue. Further, when the cleaning water 48 hits the polishing tool 26, the impact force is weak, and the removal efficiency of the residue is lowered. If the polishing device 26 is damaged, the polishing tool 26 is broken. Therefore, it is preferably 5 to 50 kPa. Further, if the relative speed of the polishing tool 26 and the water nozzle 44 is slow, the grinding efficiency of the polishing tool 26 is lowered, and if it is faster, the removal efficiency of the residue is lowered, so that it is preferably 3 to 20 m/min. The present invention has been described with reference to the detailed and specific embodiments thereof. It will be understood by those skilled in the art that various changes or modifications may be made without departing from the spirit and scope of the invention. The present application is based on the present application, which is incorporated herein by reference. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing the overall configuration of a polishing apparatus to which a polishing tool according to an embodiment of the present invention is applied. Figure 2 is a side view of the polishing apparatus shown in Figure 1. Fig. 3 is a schematic view showing a method of shaping a conventional abrasive grinding tool. I62774.doc '15-201238712 Fig. 4 is a plan view of an abrasive tool shaped by the shaping method shown in Fig. 3. Fig. 5 is a schematic view showing a method of polishing a dressing stone according to an embodiment of the present invention. Fig. 6 is a plan view of the abrasive tool which is shaped by the shaping method shown in Fig. 5. Fig. 7 is a side elevational view showing a dressing method of a grinding tool for grinding a water nozzle. [Main component symbol description] 10 Grinding device 12 Grinding head 14 Pressure plate 16 Glass holding member 18 Sealing material 20 Glass holding platen 22 Cloth material 23 Air chamber 24 Rotary shaft 26 Grinding tool 28 In, sealing material 30 Grinding tool to maintain pressure plate 40 Dressing millstone 42 Frame 44 Water nozzle 162774.doc ' 16 - 201238712 46 Spray hole 48 Washing water Pi Shaft P2 Revolving shaft G Glass plate 162774.doc . 17-