Abstract: A method is described for the manufacture of a Copper-Aluminium-Copper component (C-A-C “sandwich”) which can be used in the production of multilayer printed circuit boards, obtained by means of joining two external sheets of copper to one internal sheet of aluminium by means of a process of electro-mechanical joining, which does not require the use of additional material (such as, for example, an adhesive) and guarantees a consistently high level of quality. The joining process, normally continuous, is based on the use of a sonotrode to effect ultrasonic welding, wherein a single ultrasonic weld provides two joining zones between the two external copper sheets and the one internal aluminium sheet. According to a further embodiment, the component is manufactured with at least one layer of resin deposited externally on one of the external faces of the two copper sheets, which are not into contact with the internal aluminium sheet.