1290820 Soldering PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 8 July 1971 [11 July 1970] 32167/71 Heading B3R A soldering tool comprises a closed hollow soldering element 6 which is mounted in a holder 1 and contains a vaporizable heat transmitting medium, a part 7 of the wall of the element 6 being arranged adjacent a heat sourc e 3; in use heat received from the source 3 vaporizes the heat transmitting medium which condenses at the soldering tip 8, thereby heating the tip, and returns to the area 7 by capillary action in a porous mass 10 within the soldering element 6. The porous mass may be a ceramic lining or system of grooves, ducts, wires &c. and the vaporizable medium may be, e.g. sodium in which case the element 6 is of chromium-nickel steel. Other metals or salts are referred to as possible heat transmitting media the selection depending upon the soldering temperature. Various alternative configurations of the tool are referred to (Figs. 2-9, not shown) including some in which the soldering element has a plurality of spaced soldering tips or in which a plurality of soldering elements are provided and operated from a single heat source. The tool is stated to be of particular utility in soldering components in electronic circuits.