SINGLE ALLOY SOLDER CLAD SUBSTRATE

• Main Authors: BANERJI, KINGSHUK, BRADLEY, EDWIN, L., III, MULLEN, WILLIAM, B., III
• Format: Patent
• Language: English; French
• Published: 06.06.1996
• Edition: 6
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MACHINE TOOLS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; PRINTED CIRCUITS; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

A solder clad printed circuit board (100) consists of an electrically insulating substrate that has copper circuit traces (105), portions of which are solderable. A substantially planar layer (120) of a soldering composition is fused to the solderable traces, to form a solder pad that is not domed. The layer is composed of a mass of off-eutectic solder particles (115) that are fused together to form an agglomeration (120) having a porous structure. The solder particles are fused together by heating the off-eutectic solder to a temperature that is between the solidus temperature and the liquidus temperature of the solder. The solder is then cooled below the solidus temperature to solidify it. Plaquette (100) de circuit imprimé plaquée à l'aide d'un métal de brasage, qui est constituée d'un substrat isolant comportant des traces (105) de circuit en cuivre dont certaines parties sont brasables. Une couche (120) pratiquement plane d'une composition de brasage est fusionnée aux traces brasables pour former un amas de brasage dont la partie supérieure n'est pas incurvée. Ladite couche est composée d'une masse de particules (115) de brasage non eutectiques qui sont fondues ensemble pour former un agglomérat (120) à structure poreuse. Les particules de brasage sont fondues ensemble par chauffe du métal de brasage non eutectique à une température se situant entre la température solide et la température liquide du métal de brasage. Ledit métal est ensuite refroidi au-dessous de la température solide afin de se solidifier.