Abstract: A thermosonic ribbon bonding process uses a combination of a relatively low temperature and a high frequency to bond a ribbon conductor to conductive bonding sites of a system level support structure, such as a space/airborne antenna, containing circuit components whose characteristics might otherwise be degraded at an elevated temperature customarily used in device-level thermosonic bonding processes. By relatively low temperature is meant a temperature no greater than the minimum temperature that would potentially cause a modification of the circuit parameters of at least one of the system's components. Such a minimum temperature may lie in a range on the order of 25-85.degree. C., while the ultrasonic bonding frequency preferably lies in a range of from 122 KHz to 140 KHz. For gold ribbon to gold pad bonds, this high frequency range achieves the requisite atomic diffusion bonding energy, without causing fracturing or destruction of the gold ribbon or its interface with the gold pad.