Design of ultrasonic soldering machine and soldering applications with ultrasonic method

According to RoHS directives, using lead is banned in electronic applications therefore, lead-tin solder is also banned. Because of this ban, lead free solder has been started to develop. However, lead free solder is not suitable for traditional soldering methods. When lead free solder is used with traditional soldering methods, there are some problems in joints. In soldering, flux is used to wet joint well and flux residual should be cleaned with chemical agent after soldering. However flux residual and chemical agent residual cause to corrosion in joints therefore using flux is not suggested in soldering operations. At the present time, glass and ceramic surfaces are used to solder on but traditional soldering methods are not suitable for soldering on them. To resolve these problems, a new soldering methods and soldering equipment are necessary. According to these necessities, ultrasonic soldering method is determined the best method for solving these problems and ultrasonic soldering machine is designed. To test the performance of designed machine, some experimental studies are done. In these experimental studies, copper clips and nickel coated copper clips are soldered on aluminium surfaces without pre-cleaning, using flux, preheating and solder. And also tin coated copper clips is soldered on glass surface with lead free solder and without pre-cleaning, using flux and preheating.After soldering, transition zone is investigated with scanning electron microscope. To determine strength of soldering joint, tensile test is done with 5 mm/min. velocity at room temperature.