利用噴印技術製造精微結構可以降低成本減少汙染，是一個極具吸引力的技術。不過噴印的品質受很多因素影響，為了得到好的精微結構，如何得到好的液滴行為是很重要的事情，本研究針對高溫跟常溫的噴墨進行研究，探討噴印的參數對其精微結構品質的影響。
在高溫壓電噴墨的實驗部分，選取熔融無鉛銲錫Sn-Ag-Cu為墨水，改變不同的tfall時間得到不同的液滴型態，在模擬方面主要是改變噴墨頭邊界的壓力波，得到不同的壓力波型態，藉由模擬結果與實驗結果的比較來說明tfall時間對最後噴墨管內的壓力波所造成的影響。另外使用商業軟體Flow-3D來模擬銲錫液滴撞擊凝固的情形，並採用多顆液滴的模擬去得到熔融銲錫在不同液滴間距及噴覆頻率的導線品質。
常溫噴墨部分則是先選取奈米銀懸浮溶液以及硝酸銀水溶液，以這兩種水系材料為本研究的墨水。以不同的液滴間距及基板溫度為實驗條件去進行實驗，從所噴印的點陣列及導線結果來比較這兩種墨水的優劣，並且找到最適合噴印的參數。接著選用不同濃度的硝酸銀水溶液進行實驗，比較不同濃度墨水的噴印結果，找出濃度5M的硝酸銀水溶液是最適合應用在常溫噴墨製程，並藉由觀察不同濃度硝酸銀水溶液的乾燥行為，找出硝酸銀水溶液的乾燥機制。

Piezoelectric inkjet printing technology is a great manufacturing technology to produce micro-joint and micro-conductive line for the need of reduction of costs and environmental impact. The droplet behavior would effects the quality of the micro-joint and micro-conductive line. High temperature inkjet printing and low temperature inkjet printing were applied in this study for the quality of micro-joint and micro-conductive line during different inkjet factors.

Micro droplets of molten lead-free solder were ejected at 230oC using a piezoelectric inkjet printing process. The effect of the micro droplet formation of molten lead-free solder was investigated on the pulse time of the waveform. In this study, a computer-aided analytical system for simulating the shape evolution of micro droplet of molten lead-free solder in the inkjet printing process was developed based on computational fluid dynamics techniques. The simulation results were validated with experimental observations. The numerical results were used to understand the mechanisms of the extrusion of the liquid column, the contraction of the liquid thread, and the pinch-off of the liquid thread at the nozzle exit. A commercial software Flow-3D was adopted to simulate the fluid dynamics and thermal transients of molten solders after deposited on the substrate in order to predict the morphology and line width of micro-conductive line during different step sizes or deposition frequencies .

Two silver containing solutions were employed in this study for the fabrication of conductive patterns using inkjet printing. Line patterns with various droplet interspaces sizes of 10, 20, 30, and 40 μm were printed and evaluated. Moreover, the morphologies of line patterns were also investigated under different substrate temperatures of 25, 50, and 90℃ in this study. Aqueous silver nitrate inks of 1, 5, and 10 molarity (M) were employed in a piezoelectric inkjet printing apparatus. The actual printing qualities of array and line patterns are then analyzed by variation of dot interval and substrate temperature. Unsteady spreading features of printed array and line patterns on hydrophilic glass are found to be due to silver nitrate crystal during droplet drying, which is dominated by solute concentration and substrate temperature. The characteristics of drying progress for silver nitrate solutions were investigated after measuring contact angle on the prepared glass substrates. Due to the crystallization of silver nitrate, the decrease of local surface tension was induced with decreasing solute concentration.

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