Abstract: An arrangement of applying flux in solid, liquid or gaseous form directly to the solder wave avoids prefluxing of printed circuit boards or other elements to be soldered or solder wetted. The process for wave soldering an element comprises the steps of forming a solder wave above a solder reservoir, applying a flux directly to the solder wave separately from a shield gas delivery means to blanket the solder wave, and conveying the element through at least a portion of the solder wave. The process is applicable to wave soldering under a shroud wherein a gas shield is supplied by diffusers under the shroud, the flux being applied by at least one gas applicator directly to the solder wave.

Abstract: An apparatus and process prepares surfaces on components, boards and the like for assembly and solder joining. Oxides and other coatings can be removed from surfaces to be soldered without having to solder coat surfaces prior to joining. A polymer and an activator combination is applied to the surfaces, the polymer being thermally de-polymerizable and the combination removing oxides from the surfaces. The surfaces are heated after application of the polymer and activator to de-polymerize the polymer. Solder is then applied to solder join the surfaces.

Abstract: A cover or shroud extends over a solder reservoir and has a slot for a solder wave to protrude therethrough. Gas is provided to blanket the solder wave and the shroud is positioned to reduce solder from contacting elements that are conveyed through the solder wave. The devise comprises a solder reservoir having at least one solder nozzle projected therefrom, a pump for forming a solder wave from the nozzle, a cover for covering at least a portion of the reservoir containing the solder wave, the cover having a longitudinal slot for the solder wave to pass therethrough and contain solder splatter caused by the solder wave falling into the solder reservoir. A gas supply provides gas under the cover and also provides a gas blanket over the solder wave, and a conveyor moves the element in a predetermined path over the cover ensuring at least a portion of the element passes through the solder wave.

Abstract: A cover plate extends over at least part of a solder reservoir and has a slot for a solder wave to extend up above the cover plate. Shield gas is supplied under the cover plate to blanket the solder wave and prevent air from contacting the solder wave and circuit boards passing through the solder wave. Circuit boards are generally supported by conveyor fingers at side edges and the fingers pass through the solder wave. End shrouds are provided at both ends of the solder wave to prevent the entry of air through the conveyor fingers and to ensure that the side edges of the circuit board are uniformly blanketed by shield gas directed to the side edges passing up through the slot in the cover plate. The under surface, front edge, back edge and side edges of a circuit board are therefore uniformly blanketed by shield gas as the board passes through a solder wave.

Abstract: A cover plate extends over at least part of a solder reservoir and has a slot for a solder wave to extend up above the cover plate. Shield gas is supplied under the cover plate to blanket the solder wave and prevent air from contacting the solder wave and circuit boards passing through the solder wave. Circuit boards are generally supported by conveyor fingers at side edges and the fingers pass through the solder wave. End shrouds are provided at both ends of the solder wave to prevent the entry of air through the conveyor fingers and to ensure that the side edges of the circuit board are uniformly blanketed by shield gas directed to the side edges passing up through the slot in the cover plate. The under surface, front edge, back edge and side edges of a circuit board are therefore uniformly blanketed by shield gas as the board passes through a solder wave.

Abstract: A cover plate or shroud extends over a solder reservoir and has a slot for a solder wave to extend up above the cover plate. A reduced oxygen atmosphere is supplied from gas outlets under the cover plate on both sides of the solder wave. Furthermore a gas knife is located to direct a stream of gas on an element such as a circuit board as it passes through the solder wave. The cover plate or shroud provides reduced oxides on the solder surfaces and the gas knife removes excess solder on elements that have been solder coated. The apparatus has a solder reservoir for holding solder with a solder nozzle projecting therefrom and a pump for forming a solder wave from the nozzle. Two solder waves may be provided each with their own cover plate and gas supplied on each side of each wave below the cover plate.

Abstract: The application of electrochemical reduction treatment liquids and electroless reduction treatment liquids to elements such as circuit boards for cleaning metallic surfaces in preparation for soldering is accomplished using a wave of the treatment liquid over a liquid tank. A wave treatment has advantages over spraying, which causes too much atomizing, and dipping, which is slow and requires complicated conveyors that are multi-directional. The method comprises forming a wave of reduction treatment liquid in an atmosphere having a limited included oxygen content and passing components through the wave so the reduction treatment liquid contacts the surfaces to be solder coated.

Abstract: A preheater for a wave soldering machine has high volume convection heating permitting components on circuit boards to be heated to more uniform temperatures throughout the assembly and more rapidly without damage to the components, the assemblies or both. The machine comprises a conveyor for circuit assembly boards, a housing through which the conveyor passes having an entrance and an exit, and a plurality of heating zones in the housing extending along the conveyor. Dividers are provided between heating zones and apertured heating panels are disposed in each of the zones with a space behind each of the panels and a recirculating gap around each of the panels. A fan is positioned in the space behind each of the panels for recirculating gas, either air or inert gas through the panels and the recirculating gap.

Abstract: A solder nozzle to produce a smooth turbulent free solder wave has at least one air jet associated therewith to remove solder icicles and bridges that can form on the under surface of circuit boards and other elements. The circuit boards move in an upward inclined path in the direction of travel and after passing through the solder wave an air knife projects a non-oxidizing gas with sufficient force to remove excess solder. The soldering can occur in a non-oxidizing gas enclosure such as an inert gas, or a reducing gas, and vibrating the solder wave below ultrasonic frequencies can assist in the soldering.

Abstract: In a liquid cleaning process and apparatus where work pieces such as printed circuit boards are cleaned in an isolated enclosure, there is provided an inert gas purging system within the enclosure and a recycling condenser within the isolated enclosure to recycle all vapors from cleaning tanks within the enclosure. The apparatus has a cleaning tank and a water tank, an isolated enclosure extends between the tanks and has liquid seal dividers that extend down into the tanks. The work pieces pass on a conveyor through the cleaning tank, under a first divider, and into the enclosure where cleaning occurs. The work pieces then pass through the water tank under the second divider. A condenser is positioned above the isolated enclosure which condenses vapors rising from the enclosure and the condensate is recirculated to the cleaning tank and the water tank.

Abstract: A cover plate extends over a solder reservoir and has a slot for a solder wave to extend up above the plate, a gas excluding oxygen is supplied under the cover plate and flows up through the slot on both sides of the solder wave to blanket the solder wave. It has been found that oxygen content on the surface of the solder and on the solder wave is reduced so that clean oxide free soldering occurs. The apparatus has a solder reservoir for holding solder with a solder nozzle projecting therefrom, a pump for forming a solder wave from the nozzle, a cover plate for covering at least a portion of the reservoir having a longitudinal slot for the solder wave to pass therethrough. Provision is made for supplying pressurized gas, which is oxygen free, to pass upwards through the slot on both sides of the solder wave to provide a gas blanket over the solder wave, and a conveyor conveys elements to be soldered to pass through the solder wave.

Abstract: A melting casting process produces meltable metal cores for subsequent molding of components made of plastic material and encapsulated components such as turbine blades so they may be held for machining. The process utilizes a double acting piston in a cylinder to permit unlimited dispensing capacity without having to pause between piston strokes. The apparatus comprises a tank for containing molten metal, a double acting cylinder having both ends closed and an injection piston therein and an operating mechanism for reciprocating the piston in the cylinder. Valve mechanisms are provided so that when the piston is moved in either direction in the cylinder, a flow of molten metal passes through an injection passageway into a die, and molten metal from the tank fills the space behind the moving piston thus the cylinder always remains full of molten metal.

Abstract: A multiple metallic core assembly for use in production of a plastic injection-molded component is formed by injecting molten metal alloy into a core die at a fill stage of an indexing system, indexing the core die through a cooling stage to an unloading stage, and removing the core from the core die and inserting the core in one of a plurality of locations of the core assembly. Individual cores are continued to be formed as discussed above until all the locations of the core assembly are filled, and the core assembly is complete. Therefore, the core assembly is removed and transported to a plastic molding machine to produce the plastic component. Then, the core assembly is melted out from the plastic component in hot oil, and the molten metal alloy produced thereby is returned to a molten metal alloy tank.

Abstract: The application of electrochemical reduction treatment liquids and electroless reduction treatment liquids to elements such as circuit boards for cleaning metallic surfaces in preparation for soldering is accomplished using a wave of the treatment liquid over a liquid tank. A wave treatment has advantages over spraying, which causes too much atomizing, and dipping, which is slow and requires complicated conveyors that are multi-directional. The method comprises forming a wave of reduction treatment liquid in an inert atmosphere and passing components through the wave so the reduction treatment liquid contacts the surfaces to be solder coated.

Abstract: In the casting of metal alloys with low melting temperatures, an improved control system for lowering an injection piston in an injection cylinder is provided to avoid porosity occurring in castings. There is a fluid operated drive cylinder with a drive piston connected to the injection piston. A transducer is linked to the injection piston to provide an indication of location, and a controller compares the position of the injection piston with a predetermined time/distance profile and produces an injection stroke signal which is used to control the drive cylinder and ensure the injection piston follows the time/distance profile.

Abstract: An infrared soldering machine has an inert gas atmosphere to prevent oxidation of the solder. Heaters positioned within the machine housing above a conveyor have through apertures and fans direct inert gas down through the heaters onto the conveyor. The forced convection assists in maintaining uniform temperature across the conveyor. In order to prevent leakage of ambient air into the housing where the fan shafts protrude for connection to electric motors, a gas seal is provided at each fan shaft. The seal extends between two spaced bearings rotatably securing the fan shaft. Each electric motor is mounted away from the heat of the machine and is connected to the respective fan shaft by means of a belt drive. A novel gas curtain, which may be clamped at different angles, improves the gas seal at entry and exit locations of the conveyor.

Abstract: A wave soldering apparatus and process occurs in an atomsphere which substantially excludes oxygen. By providing a gas blanket over the solder, reduction in dross occurs and improved soldering results avoiding the necessity of removing flux residues. Gas diffusers are provided on both sides of a solder wave in an enclosure, the diffusers are placed below the path of the element to be soldered and a further gas diffuser is positioned above the element to be soldered. The gas diffusers supply a calm gas blanket over the solder wave so no turbulent movement of gas occurs within the enclosure.

Abstract: A dryer system for a liquid cleaning apparatus has a dehumidifier to remove vapors, droplets of liquid cleaning agent and recirculate dry gas onto workpieces moving on a conveyor. The dryer is particularly useful for removing solvents and restricts solvents escaping from the cleaning apparatus. The dryer has an enclosed tunnel from an enclosed liquid containing tank, a conveyor passes from the tank through the tunnel towards an exit. A dehumidifier is associated with the tunnel to remove vapor and liquid particles from atmosphere above the tank and in the tunnel, and supplies dry gas to assist in drying workpieces leaving the tank and passing through the tunnel.

Abstract: In the casting of metal alloys with low melting temperatures, there is provided a nozzle for an interface connection between a transfer line and a die which permits misalignment and a variable height differential. Meal alloys with low melting temperatures are made for cores in subsequently molded plastic components and for encapsulating components for machining the other finishing steps. The nozzle has a base with a valve therein, a nozzle body adapted to move relative to the base to open the valve, and a spring to hold the valve closed. A sleeve joins the nozzle body and the base, and a connector on the nozzle body provides an interface connection between the transfer line and the die so that when the connector interfaces with the die, the valve is open.

Abstract: A tunnel enclosure has a fluid barrier curtain at an entry and an exit and provides an apparatus for soldering an element. The fluid barrier curtains permit an additive, such as a soldering aid or the like to be included with the fluid at the curtain. More than one zone permits different temperatures or gas atmospheres and elements are passed from zone to zone with fluid barrier curtains between. A process for soldering comprises conveying an element into an enclosed zone through an entry containing at least one fluid barrier curtain, with an additive added to fluid in the curtain, heating and soldering the element in the zone, and conveying the element from the enclosed zone through an exit containing at least one fluid barrier curtain.