Verfahren zum Weichloeten von Metallen und Weichlot zur Ausfuehrung dieses Verfahrens

In a metal soldering process, the soldering location is supplied with a reaction component which, on heating to an activation temperature (especially about 221 deg. C), reacts exothermically with another component for local heating to the soldering temperature. Preferably, the solder is a tin solder (e.g. SnCu or SnCuPb) and the reaction component may be (a) Pd and/or SnAg 3.5 (as initiating eutectic) mixed with or coated on the solder; (b) an organic or inorganic metal salt, e.g. cobalt (II) acetylacetonate; or (c) a metal-free reagent, e.g. n-nonane, which may also act as a flux. Also claimed is a solder used in the above process. USE - E.g. for soldering temperature sensitive electronic components onto circuit boards using solder pastes. ADVANTAGE - The process employs a relatively low heating temperature for reaction initiation to produce the melting temperature locally within the solder, thus permitting the use of solders with increased melting temperatures without the need for ex ternal supply of the heat required for solder melting.