傳統二氧化碳 (CO2)雷射在空氣下加工會產生缺陷如凸塊、噴濺、再凝固及熱影響區等現象，因此本研究利用金屬光罩輔助CO2雷射加工微結構，改善了因熱能累積而產生的缺陷，有效降低凸塊高度及熱影響區問題，並且避免了噴濺及燒焦的情況發生。傳統雷射加工尺度大約在200 μm左右，而利用金屬光罩之開孔尺寸限制，可使加工尺度降低到58.2 μm左右，此尺度比雷射光斑尺寸還小，突破了傳統雷射加工的限制。所有缺陷產生的情況，皆與熱能的累積有關，因此本研究模擬了雷射加工之溫度場，發現金屬光罩輔助雷射加工其基材的最高溫度大大的降低，因此證明金屬光罩可以有效的隔離並且傳遞掉在加工過程中產生的多餘熱量。可以運用於導光板、微針陣列、材料改質和生物微流體晶片的製作，並可以有效的取代此尺寸的半導體製程。
利用CO2雷射加工有成本較低、加工彈性較高、和製程迅速之優點，並利用金屬光罩解決了傳統雷射加工十字型微流道時產生的阻塞問題，因此未來可利用於血液檢測和微流體晶片的製作。本論文成功的利用此金屬光罩輔助CO2雷射加工微透鏡陣列應用於導光板製作，改變雷射功率與掃瞄速度加工出不同形貌之微結構，並且對不同陣列的導光板進行光學性質分析。利用此製程製備出之導光板搭配使用一片擴散膜與兩片菱鏡片，其均齊度可達近80 %，已達市售產品均齊度要求75 %。

Traditional CO2 laser micromachining in air-cooling environment has some defects, such as bulges, splashes, resolidification and heat-affected zone. In this thesis we use the Foil-Assisted CO2 LAser Micromachining (FACLAM) to fabricate the microstructures on the materials. From the results, FACLAM not only improved the defects produced by heat accumulation, but also reduced the size of the bulges and heat affected zone. In addition, it diminished the splashes and scorch during the process. Compared with traditional CO2 laser micromachining in air-cooling environment, FACLAM was breaking through the restriction of laser machining that reduced the processing scale to as small as 58.2 μm, which is much smaller than the laser spot size. All of the defects result from the heat accumulations, so we simulated the temperature distribution of the laser micromachining. The results showed the heating temperature can be greatly reduced by using FACLAM. It evidences that the enhancement of high quality of the ablated surface by FACLAM is achieved because the metal foil mask can significantly block and conduct the remaining heat out to reduce the surface temperature during ablations. It can be applied for light quide plate, microneedle arrays, laser modification of materials and bio-microfuidic chip. Using FACLAM can effectively replace semiconductor process above 50 μm-scaled.
The CO2 laser processing has been widely applied in microfabrication and microfluidic chips because of the advantages of low cost, flexibility, easy-fabrication, and environmental-friendly. Using FACLAM to fabricate the cross-junction microchannels, we can fabricate the channels without the occurrence of cloggings. Changing the arrangement of metal foil, it can also let us use the FACLAM to fabricate the Light guide plate (LGP). The different laser power and scanning speeds with different microstructure shapes are discussed. Furthermore, the optical properties of various microstructure shapes and microstructure arrangements are analyzed. From the result, the uniformity of light guide palte with a diffusion plate and two prism plates was about 80% which is higher than the average uniformity of commercial products with 75%.

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