[[alternative]]Displacement Study on Ultrasonic Transducer for Thermosonic Flip Chip Bonding

碩士機電工程學系[[abstract]]本文主要目的在於針對熱超音波LED覆晶接合製程，其關鍵技術設備超音波振動子，做深入的分析探討。超音波頭之位移表現是影響覆晶接合品質的重要因素，為實際了解運動位移，並有效提升LED鍵合之效率，研究中藉由GiD與ATILA模擬軟體，針對超音波振動子進行有限元素分析，以此獲得振動子之位移情形、阻抗匹配及驅動頻率等主要特性，再以實驗的方式，透過雷射速度計與LCR測試儀等量測儀器進行驗證，並歸納出可靠之實驗數據，作為覆晶製程的參考。在超音波振動子未裝接合工具( Bonding tool)的條件下，分析其主要振動能量的傳遞，超音波頭運動位移的實驗中，研究發現真空吸嘴與超音波頭所擺放的位置，對整體振動子機械結構之共振頻率會造成影響，進而產生不同之超音波振動位移。據此，尋求接合工具的最佳擺放位置，並使超音波傳遞效果達到最高，提升LED與基板間的結合力。[[abstract]]In this thesis, the experiment study of ultrasonic transcucers for thermosonic Flip-Chip bonding is presented. Improving the efficiency of ultrasonic transducers plays an important role in the bonding process. However, the vibration displacement of tool is a key factor that affect the efficiency of bonding. In order to obtain the actual movement of ultrasonic transducer, Finite Element Method is a appropriate way to get more detailed information. In this thesis, a ultrasonic transducer model is constructed to analyze structure interaction by using ATILA code and GiD graphical interface. To verify the reliability of simulated results, the impedance characteristic and resonance frequency of the transducer have been measured using a LCR meter. Moreover, at several experiment results demonstrate, different mounting position of bonding tool of the transducer affects tool tip displacement. ATILA can be used to estimate the best mounting position. A Laser Doppler Vibrometer is then to measure the vibration amplitude of the tool experimentally. It is shown the great performance of ultrasonic energy transmission will enhance the bonding quality between LED and substrate