| 摘要: | 本研究分別以304 不鏽鋼與石墨兩種目標基板以雷射誘發電漿輔助微加工
技術(Laser-induced plasma assisted micromachining, LIPMM)結合掃描路徑之規劃於玻璃上製作微針尖陣列，以不同的雷射參數使陣列產生不同形貌的表面結構，並經由加高墊片(Spacer)的厚度以觀察Plasma 在不同距離的情況下對表面結構造成的影響，並比較304 不鏽鋼與石墨板目標基板所誘發的Plasma 對玻璃結構所造成的差異。
本研究的第一部分介紹微陣列結構的形成，之後比較玻璃與對應之目標基板石墨在不同掃描次數下的形貌，發現初始掃描次數為5 次的石墨表面結構會受到雷射路徑影響呈現7x7 的方格陣列，增加掃描次數到50 次時，因為玻璃底層表面結構的改變使得部分雷射光聚焦於陣列中方格的中心形成黑孔結構。
第二部分探討在不同條件(掃描次數、功率、間距、目標基板)下的表面輪廓，如塔尖高度、塔尖寬度、陣列深度與底層高低差，經過觀察後發現塔尖高度、塔尖寬度、陣列深度皆會隨著掃描次數與功率而增加。把間距從225 um 增加到700 um後觀察到塔尖高度與陣列深度也會隨著功率增加，但值皆小於間距為225 um時同參數的情況，這是因為Plasma 強度會隨著距離而遞減的關係，至於塔尖寬度變化幅度差異不大。最後把目標基板換成石墨，從熱性質的方面去討論表面輪廓的差異，發現到石墨產生Plasma 較304 不鏽鋼困難，所以形成的塔尖高度、陣列深度較使用304 不鏽鋼的情況下低。;This study aims at fabricating micro-pin arrays on a glass substrate using the technique of laser-induced plasma assisted micromachining (LIPMM). The ablating
plasma is generated by irradiating laser light on two different target substrates, 304 stainless steel and graphite, respectively. Various surface morphologies of micro-pin arrays, obtained by different laser operating parameters and scan schemes, are examined and discussed. The influence of plasma intensity on the glass ablation and
the resulting surface morphology of the micro-pin array is investigated by varying the spacer’s thickness, the distance separating the glass from the target substrate.
In the first part of this study, we introduce the formation mechanism of micro-pin arrays and compare both surface morphologies of the glass and graphite target substrates at different scan schemes and scan times. We find that the surface morphology of graphite substrate shows a particular relationship with the glass surface profile. When the scan times is 5, the graphite substrate displays a 7 × 7 array as the scan path. As the scan times is increased to 50, a black hole at the center of the square of array is observed. It is because the convex pyramid structures on the glass behaving as focusing centers that converging laser light and ablating the square array centers.
The second part of this study focuses on the surface profile (pin height, pin width, array depth and the height difference from the original glass surface) using different
experiment parameters (scan times, power, the thickness of spacer, and target substrate). We find that the pin height, pin width, and array depth are increased with power and scan times. When the thickness of spacer is increased to 700 um, the pin height and array depth are directly proportional to the laser power, but both of them are smaller than that of 225 um thickness. Finally, if graphite plate is served as the target substrate, the pattern of micro-pin array is shallower. This is because the plasma formation threshold of the graphite plate is higher than that of stainless steel. |
