The Sunbonder USM-IV portable ultrasonic soldering device makes it possible to adhere solder directly to materials that previously were considered "unsolderable." It can be used to solder directly onto such materials as aluminum, stainless steel, titanium metal oxides, ceramics, and glass. The device operates in basically the same way as a conventional soldering iron, but it does not require flux. When used with a specially formulated solder called Cerasolzer, the Sunbonder ultrasonic method replaces other, more-complex bonding methods such as silver baking, resin bonding, and indium soldering. Cerasolzer combines with oxygen in the soldering material to form an extremely strong chemical bond at the interface of the two materials. The resulting bond has a high degree of electrical conductivity, adhesive strength, air/water tightness, and weather/humidity resistance.