Studies on Ultrasonic Micro Welding Using High-Frequency Vibration

研究了频率为27 kHz~800 kHz的高频复合振动超声焊接系统的振动及焊接特性。高频和复杂的振动系统具有椭圆到圆形或矩形到正方形的轨迹，适用于各种试件的超声波焊接，包括相同和不同的金属试件，以及半导体针尖的直接焊接和各种电子器件的无焊焊。该复杂振动系统由一维狭缝结构纵扭振动转换器、阶梯变幅杆和纵向振动换能器组成。27 kHz和100 kHz的复合振动焊尖具有足够的面积，可用于各种焊接试件的面积为6 mm~8 mm。成功地连接了厚度为0.3 mm~1.0 mm的铝板试件，其焊接强度与铝试件的强度几乎相同，且与试件方向无关。100 kHz系统所需的振动幅值小于27 kHz系统所需的振动幅度，并提出了40 kHz~200 kHz的纵向复合横向振动系统，以获得较大的焊接尖端面积，如10 mm~20 mm方形，对应于连接到衬底的带有大量凸块的大型半导体针尖。纵向复合横向振动系统由一个21 mm方形阶梯形复合横向振动杆、两个横向振动回路位置成直角相交的纵向振动系统和一个带静压源的焊接框架组成。复合振动源固定在焊接框架内的横向节点位置。40 kHz复合振动焊尖以大于1.0 mm/S(峰零值)的振动速度振动，并在整个焊尖均匀振动。

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.