METHOD FOR MANUFACTURING QUARTZ GLASS FILAMENT

To provide: a method for manufacturing a quartz glass filament used for a semiconductor package substrate, excellent in surface smoothness, having very small variation in mass and thickness and excellent in dimensional stability; a quartz a glass strand; and a method for manufacturing quartz glass yarn.SOLUTION: The method for manufacturing a quartz glass filament comprises heating and drawing a quartz glass ingot to manufacture a quartz glass thick fiber and heating and drawing the quartz glass thick fiber to manufacture a quartz glass filament. When manufacturing the quartz glass thick fiber, the initial response amount proportional to a deviation size between the target diameter value of the thick fiber after the heating and drawing and a measured value and a control operation amount corresponding to the cumulative value of a deviation between the target diameter value and the measured value are reflected on a thick fiber drawing speed, and the control operation amount corresponding to the cumulative value of a deviation between the target speed of the thick fiber drawing speed and an actual speed is reflected on a speed sending the ingot into the furnace.SELECTED DRAWING: Figure 4 【課題】半導体パッケージ基板に用いられ、表面平滑性に優れ、質量および厚さバラツキが非常に少なく、寸法安定性に優れた石英ガラスフィラメント、石英ガラスストランド及び石英ガラスヤーンの製造方法を提供する。【解決手段】石英ガラスインゴットを加熱延伸せしめて石英ガラス製太繊維を製造した後、前記石英ガラス製太繊維を加熱延伸せしめて石英ガラスフィラメントを製造してなる石英ガラスフィラメントの製造方法であって、前記石英ガラス製太繊維を製造するにあたり、前記加熱延伸後の太繊維の目標線径値と測定値の偏差の大きさに比例した初期応答量と、目標線径値と測定値の偏差の累積値に応じた制御操作量を太繊維の線引き速度に反映させ、且つ太繊維の線引き速度の目標速度と実速度の偏差の累積値に応じた制御操作量をインゴットの炉内への送り速度に反映させるようにした。【選択図】図４