Studies on Ultrasonic Micro Welding Using High-Frequency Vibration

研究了27 kHz ~ 800 kHz高频和复杂振动超声焊接系统的振动和焊接特性。具有椭圆到圆形或矩形到正方形轨迹的高频复杂振动系统，可有效地用于包括相同和不同金属样品在内的各种样品的超声焊接，以及各种电子器件的半导体尖端和封装的无焊料直接焊接。该复杂振动系统由一维纵扭变换器、阶梯喇叭和纵向振动换能器作为驱动源组成。27 kHz和100 kHz的复合振动焊头有足够的6 ~ 8 mm平方的面积用于各种焊接试样。0.3 mm ~ 1.0 mm厚度的铝板试件成功连接，焊缝强度与铝试件强度基本相等，且与试件方向无关。100 kHz系统所需的振动幅值小于27 kHz系统所需的振动幅值。此外，提出了40 kHz至200 kHz的纵向-复合横向振动系统，以获得10 mm至20 mm平方的大焊接尖端面积，对应于具有大量凸起的大型半导体尖端与衬底连接。该纵向-复合横向振动系统由一根21 mm方的阶梯形复合横向振动杆、两个直角交叉的横向振动环位置的纵向振动系统和一个带静压源的焊接架组成。复合振动源固定在焊接框架的横向节点位置。40 kHz复合振动焊接尖端振动速度大于1.0 mm/s（峰至零值），整个尖端均匀振动。

The vibration and welding characteristics of high-frequency and complex vibration ultrasonic welding systems of 27 kHz to 800 kHz were studied. High-frequency and complex vibration systems, which have elliptical to circular or rectangular to square locus, are effective for ultrasonic welding of various specimens including the same and different metal specimens, and for direct welding of semiconductor tips and packaging of various electronic devices without solder. The complex vibration systems consist of a one-dimensional longitudinal-torsional vibration converter with slitted parts, a stepped horn and a longitudinal vibration transducer as a driving source. The complex vibration welding tips of 27 kHz and 100 kHz have enough area of 6 mm to 8 mm square for various welding specimens. Aluminum plate specimens of 0.3 mm to 1.0 mm thickness were successfully joined with weld strengths almost equal to aluminum specimen strength, and independent to the specimen direction. Required vibration amplitude of 100 kHz system is less than that of 27 kHz system.Furthermore, the longitudinal-complex transverse vibration systems of 40 kHz to 200 kHz were proposed to obtain large welding tip area such as 10 mm to 20 mm square corresponding to large semiconductor tips with large number of bumps for connecting to the substrates. The longitudinal-complex transverse vibration system consists of a stepped complex transverse vibration rod of 21 mm square, two longitudinal vibration systems which are in the transverse vibration loop positions crossed at a right angle, and a welding frame with a static pressure source. The complex vibration source is fixed at a transverse nodal position in the welding frame. The 40 kHz complex vibration welding tip vibrates at vibration velocity of more than 1.0 mm/s (peak-to-zero value) and vibrates uniformly throughout the tip.