基於節省生產成本考量及環保因素考量，CD-R(Compact Disc Recordable)光碟片之感光染料旋轉塗佈製程中，感光染料減量是一個重要之議題，本研究之實驗流場觀測圖顯示，經由與平滑型光碟片基板之旋塗流場圖相互比較後發現，表面具有預製螺紋狀溝槽之光碟片基板會對不穩定手指狀現象及可形成完全覆膜之時間有顯著之影響。旋塗製程中，光碟片基板表面之風剪氣流將會影響注入感光染料之流場分佈，特別是在塗佈較大面積之區域時。因此，於塗佈液注入過程中，在低基板轉速下所得之塗佈效果要比在高基板轉速下來的好。在塗佈基板轉速為300 rpm時，可以獲得完全覆膜之噴嘴移動速率比在塗佈基板轉速為500 rpm條件下較為寬廣。研究結果同時提供出實驗參數包括注液速率、注液量及噴嘴移動速率之具溝槽光碟片基板可完全覆膜關係圖等相關結論，藉由選取適當之注液速率及噴嘴移動速率進行旋塗製程時，將可有效把感光染料使用量減低至0.05 mL。 本研究另針對三種不同之塗佈液注入方式：自由釋放液滴法(Released Drop)、中心注入法(Centered Injection)及螺旋注入法(Spiral Injection)，探討此三種不同之塗佈液注入方式於旋轉塗佈製程中對塗佈效率之影響，旋塗用基板為晶圓基板。依據實驗流場觀測圖可得知，塗佈液注入方式對於基板表面液膜的可形成完全覆膜之時間、液膜波前之最大覆膜半徑(Rmax)及最小塗佈液注液量有著顯著之影響。經由與自由釋放液滴法及螺旋注入法之旋塗流場圖相互比較後發現，於塗佈液黏度較低時，利用中心注入法進行旋塗時，因為具有最小臨界半徑Rc之緣故，使得其在基板表面形成完全覆膜之塗佈時間比利用自由釋放液滴法及螺旋注入法在基板表面形成完全覆膜之塗佈時間較為長。在邦得數Bo (Bond Number)約為定值之實驗參數條件下，於旋轉雷諾數較高時，螺旋注入法之無因次液膜波前之最大覆膜半徑的值比自由釋放液滴法及中心注入法之無因次液膜波前之最大覆膜半徑的值較為小，而當於旋轉雷諾數較低時，螺旋注入法之無因次液膜波前之最大覆膜半徑的值則大於自由釋放液滴法及中心注入法兩者之無因次液膜波前之最大覆膜半徑的值。 Reducing the amount of dye used in the spin-coating process for compact disc-recordable (CD-R) is essential for cost reduction and environmental consideration. The results of flow visualization show that, compared with that on a smooth substrate, the patterned roughness on the pregrooved substrate does affect the fingering instability and the amount of time needed for fully coating the substrate. The airshear flow above the disc will affect the injection of dye onto the disc, particularly in an area of larger radius. Therefore, a higher disc rotation speed in the stage of dye injection is not necessarily better than a slower one. The range of nozzle-moving speed V, which can be used for fully coating the substrate, is wider at 300 rpm than that at 500 rpm. The regime maps for injection rate Q, nozzle-moving speed V, and injection volume show that by choosing appropriate Q and V, the amount of dye used was reduced to 0.05 mL. The study investigates how the method of liquid dispensing, including released drop, centered injection and spiral injection, affects the coating efficiency during spin coating processes. The flow visualization indicates that the method of liquid dispensing has a significant effect on the time needed to fully coat the wafer, the minimum liquid volume required for fully coating, and the maximum attainable radius of liquid front Rmax. Compared with the released drop and the spiral injection, the centered injection takes the longest time to fully coat the wafer mainly due to its very small critical radius Rc. Under a constant Bond number Bo, Rmax for the spiral injection is slightly smaller than those for the released drop and centered injection in the region of high rotational Reynolds number Rew, while the Rmax for the spiral injection becomes the largest in the region of low Rew.
