Abstract: An optic module contains a flexible circuit board forming a cable which connects between an optical sub-assembly and a rigid interconnect structure within the optic module. One end of the cable includes lands proximate to through holes for soldered connection to pins which extend from the optical sub-assemblies. At the other end of the cable leads extend across interconnection pads on the surface of the rigid interconnect structure for soldered connection. The top surface of the interconnect pads is 10/90 (Sn/Pb) solder to provide a high temperature soldered joint. Solder flux can not be used because cleaning solvents would contaminate the interconnect structure. An atmosphere of formic acid mixed with nitrogen surrounds the lead and pad and a fluxless solder joint is formed.

Abstract: An optic module contains a flexible circuit board forming a cable which connects between an optical sub-assembly and a rigid interconnect structure within the optic module. The cable includes lands proximate to through holes for soldered connection to leads which extend from the optical sub-assemblies and are substantially smaller than the hole. A soldering bridge comprising several separate tabs equally spaced about the land and which project from the land into the hole and are very flexible in relation to the lead so that the lead can be placed in any radial position within the hole, but regardless of the position of the lead within the hole the projections of the soldering bridge project close enough to the lead so that during wave soldering a joint of desired configuration is produced. The soldering bridge can be integral with the land so that the bridge helps connect the solder to the land allowing the land to be smaller and thus providing for closer spacing between connection holes.

Abstract: A machine for connecting leads of a substrate to solder pads, the machine including a motor moving a conveyor for automatically positioning the substrate in the machine so that a bottom side of the substrate has a lead placed in contact with a solder pad without flux for reflow soldering. Additionally, a laser is present to heat the solder pad in an atmosphere of an inert gas mixed with formic acid for reflow soldering of the lead to the reflowed solder pad. A probe can be used to press the lead against the solder pad which may be made of Molybdenum to prevent solder adhesion. The solder pad can be made of 20% tin and 80% lead.

Abstract: An optic module contains a flexible circuit board forming a cable which connects between an optical sub-assembly and a rigid interconnect structure within the optic module. One end of the cable includes lands proximate to through holes for soldered connection to pins which extend from the optical sub-assemblies. At the other end of the cable leads extend across interconnection pads on the surface of the rigid interconnect structure for soldered connection. The top surface of the interconnect pads is 10/90 (Sn/Pb) solder to provide a high temperature soldered joint. Solder flux can not be used because cleaning solvents would contaminate the interconnect structure. An atmosphere of formic acid mixed with nitrogen surrounds the lead and pad and a fluxless solder joint is formed by laser soldering.

Abstract: An optic module contains a flexible circuit board forming a cable which connects between an optical sub-assembly and a rigid interconnect structure within the optic module. The cable includes lands proximate to through holes for soldered connection to leads which extend from the optical sub-assemblies and are substantially smaller than the hole. A soldering bridge comprising several separate tabs equally spaced about the land and which project from the land into the hole and are very flexible in relation to the lead so that the lead can be placed in any radial position within the hole, but regardless of the position of the lead within the hole the projections of the soldering bridge project close enough to the lead so that during wave soldering a joint of desired configuration is produced. The soldering bridge can be integral with the land so that the bridge helps connect the solder to the land allowing the land to be smaller and thus providing for closer spacing between connection holes.