[[alternative]]Experimental and analytical study of ultrasonic bonding tool for Thermosonic Filp Chip Bonding Process

碩士機電工程學系[[abstract]]本文主要目的在探討LED熱超音波覆晶接合之最佳化參數設定，以及其中關鍵技術中之壓電超音波震動子部份，使製程條件能達到低溫低壓之接合結果。研究中利用田口分析法探討四項主要控制參數以找尋最佳製程組配；四項參數分別為接合壓力、接合溫度、超音波接合時間及功率等，其中壓電超音波之輸出效率為提升覆晶接合力主要影響因子，因此改善超因波輸出功率為提升覆晶接合力主要關鍵技術；然在多次量測超音波頭運動位移的實驗中，發現真空吸嘴與超音波頭所擺放位置，影響了壓電共振頭輸出運動位移與震盪頻率。據此，尋求吸嘴的最佳擺放位置，並使超音波傳遞效果達到最高，將成為LED與基板間的結合力提升之重要因素。研究中使用商用軟體GID與ATILA進行模擬分析，提供實驗可靠的依據，並使用LCR-HiTESTER量測其阻抗與頻率之特性，找尋其最佳共振點，並利用雷射位移計量測其位移特性之變化，驗證實驗之結果，進而提升熱超音波覆晶接合之良率且進一步的降低溫度及下壓力等製程之參數。[[abstract]]This paper aims to investigate the best processing parameters for LED flip chip bonding. Low temperature with lower bonding pressure plays an important role for the bonding process. The thermosonic bonding parameters on LEDs involve different bonding temperatures, different bonding force, different bonding time and different ultrasonic power. Improving the efficiency of ultrasonic transducers plays an important role in the bonding process. However, the placement location of the tool on the transducer affects the transducer work efficiency. Therefore, to analyze the piezo-transducer and bonding tool provided reliable experimental basis by use of the commercial package GID & ATILA software. Finding the resonance frequency of the transducer was measured with LCR test instrument. Laser Doppler vibrometer is attained for measuring the ultrasonic motion based on ultrasonic propagation for analyzed piezo transducer. Experimental results finds the less force and lower bonding temperature parameter combination are reached a promising solution for flip-chip LED in thermosonic bonding