Jiromaru Tsujino

Ultrasonic butt welding of aluminum, aluminum alloy and stainless steel plate specimens.

Welding characteristics of aluminum, aluminum alloy and stainless steel plate specimens of 6.0 mm thickness by a 15 kHz ultrasonic butt welding system were studied. There are no detailed welding condition data of these specimens although the joining of these materials are required due to anticorrosive and high strength characteristics for not only large specimens but small electronic parts especially. These specimens of 6.0 mm thickness were welded end to end using a 15 kHz ultrasonic butt welding equipment with a vibration source using eight bolt-clamped Langevin type PZT transducers and a 50 kW static induction thyristor power amplifier. The stainless steel plate specimens electrolytically polished were joined with welding strength almost equal to the material strength under rather large vibration amplitude of 25 microm (peak-to-zero value), static pressure 70 MPa and welding time of 1.0-3.0 s. The hardness of stainless steel specimen adjacent to a welding surface increased about 20% by ultrasonic vibration.

Transverse and torsional complex vibration systems for ultrasonic seam welding of metal plates

Transverse and torsional complex vibration systems for ultrasonic seam welding of metal plate specimens, using a 27 kHz complex vibration disk welding tip vibrating in transverse and torsional vibration modes, were studied. Using a complex vibration welding system with a welding tip vibrating in elliptical or circular locus, thick plate specimens can be welded with a more uniform and larger area compared to a conventional ultrasonic welding system. The disk welding tip vibrates in an elliptical or circular locus. The complex vibration system can continuously weld multiple parts of metal plate specimens such as heat sinks with a large number of fins.

Welding characteristics and temperature rise of high frequency and complex vibration ultrasonic wire bonding

Abstract Welding characteristics of 190 kHz ultrasonic wire bonding systems with linear, square and circular vibration loci are studied. High-frequency systems of 90 ~ 780 kHz were shown to be significantly effective compared with conventional frequency systems. The required vibration amplitude of high frequency becomes very small, i.e 0.04 μm (peak-to-zero value) at 780 kHz which is 1 30 that of 60 kHz [1–3]. Welding wire aluminum specimens 0.1 mm in diameter are joined successfully. The temperature rise at welding part is measured by thermoelectromotive force between aluminum wire and copper plate specimens, and deformation of wire specimens is measured by a height gage. Complex vibration welding tips of 190 kHz which vibrate in elliptical to circular or rectangular to square at the same or different frequencies are shown to be effective in joining welding specimens successfully in a shorter welding time and under smaller vibration amplitude, with a wider good welding domain. Temperature rise and wire deformation have a good correlation with weld strength obtained. With a high frequency longitudinal vibration system, it is very difficult to install a ceramic capillary at its tip because the dimensions of such high frequency systems as 330, 600 or 780 kHz become too small. For installing a ceramic capillary in the high frequency system, longitudinal to complex transverse vibration systems of 160 ~ 575 kHz are proposed and the vibration characteristics of the system and a ceramic capillary are measured. The capillary 1.5875 mm in diameter and 6.5 mm in projection length has one transverse vibration node along its length at 160 kHz and two vibration nodes at 515 kHz.

Welding Characteristics of Aluminum and Copper Plate Specimens Welded by a 19 kHz Complex Vibration Ultrasonic Seam Welding System

The welding characteristics of aluminum and copper plate specimens welded using a 19 kHz ultrasonic welding system with a complex-vibration welding tip were studied. The welding tip part vibrates in an elliptical or circular locus. The seam welding system uses a rotating circular disk welding tip and a shifting stage for continuous welding of the metal sheets. Using the complex-vibration system, metal plates of various thicknesses can be welded continuously at multiple positions with large and uniform welded areas and large weld strengths independently of the welding position and direction. The required complex-vibration amplitude is less than one-half of that of a conventional linear-vibration system. Aluminum-aluminum, aluminum-copper and copper-copper plate specimens were welded with weld strengths almost equal to the specimen strength.

Ultrasonic motor using a one-dimensional longitudinal-torsional vibration converter with diagonal slits

Characteristics of ultrasonic rotary motors using a longitudinal-torsional vibration converter 15 mm to 50 mm in diameter are described. To obtain large torque, ultrasonic motors using one-dimensional longitudinal-torsional converters with diagonal slits are proposed. The converters have rather simple and tough structures and are driven using only a longitudinal vibration transducer. The vibration converters are made of metal materials and have diagonal slits cut along the converter circumference adjacent to a nodal position of longitudinal vibration. The ultrasonic motors consist of a vibration converter with a driving part at its free edge, and a rotor part pressed statically to a driving surface using corned disk springs. Vibration characteristics and vibration loci at driving surfaces of these motors are measured under loaded and nonloaded conditions and under forward and reverse rotating conditions. Maximum torques over 0.3 to 23 N m were obtained by the converters 15 to 50 mm in diameter and at frequencies of 80 to 23 kHz. Maximum revolution obtained was over 550 rpm using a 15 mm diameter motor of 56 kHz.

Welding Characteristics of Ultrasonic Seam Welding System Using a Complex Vibration Circular Disk Welding Tip

The continuous welding characteristics of a 27 kHz ultrasonic seam welding system using a complex vibration circular disk welding tip are studied. The vibration characteristics of a complex vibration converter were improved compared with the prototype model. The circular disk welding tip vibrates in both transverse and torsional vibration modes and an elliptical vibration locus is obtained at the circumference of the circular disk welding tip. An ultrasonic seam welding equipment consists of a complex vibration circular disk welding tip that is driven by a longitudinal vibration system through a longitudinal-torsional vibration converter, and an automatic specimen shifting stage. A large number of aluminum plate specimens of 0.3 mm to 0.5 mm thickness and 50 mm to 300 mm length were continuously joined to a thick aluminum plate at multiple welding parts.

New methods of ultrasonic welding of metal and plastic materials

New ultrasonic welding methods of metal and plastic materials have been proposed by the author and have shown their effectiveness. For welding of thick and large metal specimens, (1) an ultrasonic butt welding method of joining thick metal specimens end to end is proposed. Large capacity vibration sources and solid-state power amplifiers of 50, 100 kW have been developed. (2) The welding method of using two vibration systems crossed at a right angle is effective, and 10 mm thick aluminum plates have been joined successfully. For medium size metal welding specimens, (3) complex vibration welding tips have been shown to be very effective, and one-dimensional complex vibration systems are developed to simplify the systems. For welding of small metal specimens, (4) higher vibration frequency, and complex vibration wire bonding systems are proposed and it is shown that they are significantly effective. Bonding systems of 60 to 600 kHz have been designed. For welding of plastic materials, (5) high frequency and two-vibration-system welding methods are effective.

Complex vibration ultrasonic welding systems with large area welding tips.

Vibration and welding characteristics of complex vibration ultrasonic welding systems of 27 and 40 kHz were studied. 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 part, a stepped horn and a longitudinal vibration transducer as a driving source. The complex vibration welding tips of 27 and 40 kHz have enough area of 6-8 mm square for various welding specimens. Aluminum plate specimens of 0.3-1.0 mm thickness were successfully joined with weld strengths almost equal to aluminum specimen strength, and independent to the specimen direction. Required vibration amplitude of 40 kHz is smaller than that of 27 kHz.

Welding characteristics of 27 kHz and 40 kHz complex vibration ultrasonic metal welding systems

Complex vibration ultrasonic lap spot and seam welding systems of 27 kHz and 40 kHz are studied. Welding characteristics of 27 kHz and 40 kHz complex vibration lap spot welding systems with a longitudinal-torsional vibration converter were compared using aluminum plate specimens. And also, a lap seam welding system with a complex vibration disk welding tip was designed. Aluminum plates of various thickness were continuously joined at multiple positions uniformly using the complex vibration system.

Temperature Rise and Welding Characteristics of Various-Frequency Ultrasonic Plastic Welding Systems

Welding characteristics and temperature increases of ultrasonic plastic welding parts over a frequency range from 27 to 94 kHz are studied. Using 27, 40, 67, and 94 kHz ultrasonic plastic welding systems, temperature increases at welding surfaces of lapped 1.0-, 2.0-, and 3.0-mm-thick polypropylene plates and polymethyl methacrylate plates are measured using 0.1- and 0.2-mm-diameter thermocouples inserted between plates, and temperature distributions at cross sections of lapped plate specimens are measured using a thermotracer. The 94 kHz vibration system used for ultrasonic plastic welding consists of a bolt-clamped Langevin-type longitudinal vibration source using four 30-mm-diameter piezoelectric ceramic (PZT) rings, a stepped horn (vibration velocity transform ratio N=3.0) and a catenoidal horn (N=3.13) with an 8-mm-diameter welding tip. The other vibration systems have similar configurations. In the case of using a higher-frequency system, increases in temperature measured at the welding parts are larger. Temperature rises are larger for lapped plate specimens than that for a one-piece specimen owing to the vibration loss of welding surfaces.