Ultrasonic Soldering is available in manual soldering and robotic
soldering systems and is designed to apply high-frequency
vibrational energy to a molten filler metal to solder parts without
flux. Ultrasonic soldering also creates strong attachments through
mechanical and chemical bonds. The vibrational energy forces the
liquid solder into tiny crevices and pores in the substrates which
helps to seal the parts and greatly increase the surface area to
which the solder can bond. Chemical bonding uses a special solder
which usually has trace amounts of aluminum, beryllium, indium,
silicon, silver, titanium, zinc and rare earth elements. These have
a strong affinity with oxygen and tend to form oxides that
chemically bind to glass, ceramics and metals. This solder is
available from Fancort in leaded or lead free composition.