Abstract: A method and apparatus for desoldering electronic components from a substrate. A vacuum is used, to enhance the flow of a hot gas under an electronic component to reflow the solder connections attaching the electronic component to a substrate. Water vapor is added to the hot gas to increase the heat capacity of the hot gas. A system for periodically changing the direction of flow of the hot gas and vacuum under the electronic component is used to uniformly heat the solder connections.

Abstract: A disposable solder receiving capsule for a hand held vacuum solder extracting desoldering tool is formed of an outer tube which is closed at one end by a porous filter and has an opening at its opposite end, and a hollow solder collection chamber part, having a tubular member with an open end and which is closed with respect to the passage of solder therethrough at an opposite end, forming a solder receiving space within it. The solder collection chamber part is concentrically positioned within the outer tube with an air plenum disposed between the closed end of the chamber part and the filter and with at least one air channel extending the length of solder collection part for providing a path for gases entering the open end of the outer tube to the plenum and the filter that is separated from the solder receiving space. For facilitating solder reclamation, the capsule can be formed entirely of materials which are shape-sustaining when exposed to a temperature of 400° F.

Abstract: The present invention relates to a solder ball shaping tool and a method for using the tool. In a substrate there is formed a series of depressions. The tool is pressed onto a ball grid array and the ball grid array is realigned either with simple pressure or pressure assisted by heating. Where a solder ball may have been deposited upon a die or a chip package in a diameter that exceeds that of the designed diameter, a corral tool is used to substantially conform the solder ball to design dimensions and a design location. As the corral tool is pressed against the solder ball, portions of the solder ball will reflow both into the substrate depression and into the corral. Where the total volume of the solder ball does not exceed that of both the corral and the substrate depression, the corral tool is adequate to achieve a designed solder ball height.

Abstract: A weld bead chopper is provided, for use in combination with a scarfing tool which is intended to scarf a longitudinal weld bead from a tube. The chopper has a) a chopper blade which is rotatable about an axis which is substantially perpendicular to a longitudinal axis of the tube, and b) a stationary blade which is cooperable with the rotatable blade. The cooperating chopping surfaces of the rotatable and stationary blades are at a short distance from the weld bead, e.g. less than 100 mm, and preferably from 20 to 50 mm. The scarfed weld bead enters an enclosed throat which has walls to guide a scarfed weld bead towards the cooperating chopping surfaces. The throat has a first guide adjacent to the scarfing tool which directs the scarfed weld bead towards a second guide. The second guide faces the scarfing tool, and is adapted to guide the scarfed weld bead towards the cooperating chopping surfaces.

Abstract: The invention provides a reflow furnace for an electronic assembly. The electronic assembly comprises a printed circuit board and a device on the printed circuit board. The printed circuit board has solder at a first area near the device and a metallic surface at second area distant from the device. The furnace comprises a frame, a support, a heater, and a shield. The support is secured to the frame and is capable of holding the printed circuit board. The heater is secured to the frame and is capable of heating the printed circuit board while being held by the support. The shield is secured to the frame and is positioned to prevent solder from migrating from the first area to the metallic surface at the second area while the printed circuit board is being heated.

Abstract: Method for repairing defective soldered joints, in which in a first method step a soldering material handling device is placed with a soldering material removal device at a soldering material defect point and a defective soldering material deposit is loosened from the connection with a soldering material carrier and removed, and in which in a second method step a soldering material unit from a soldering material application device of the soldering material handling device is applied to the soldering material carrier and connected to the soldering material carrier, the application device being placed at the soldering material defect point.

Abstract: A method for producing an electronic circuit device includes a repair step in which, in a case where a semiconductor device once mounted on a wiring board is defective, the defective semiconductor device is removed from the wiring board and a new semiconductor device is mounted on the wiring board. The repair step includes the steps of: removing an excessive residue of a brazing metal residue remaining on lands of the wiring board from which the defective semiconductor device has been removed and leaving a uniform amount of the brazing metal residue on the lands; aligning the new semiconductor device with the wiring board; and melting the brazing metal residue which is made uniform and remains on the lands and projecting electrodes of the new semiconductor device by heating, thereby connecting the new semiconductor device to the wiring board.

Abstract: A method of assembling a substrate and die in a flip chip configuration uses a non-hazardous cleaning solvent to clean the flux residue. The non-hazardous cleaning solvent utilized is Ionox obtained from Kyzen Corporation. Optimized process parameters are: time 10-30 minutes, temperature 70-90.degree. C., pressure 40-70 psi, rotation speed and reversals 100-1000 rpm and 24-100 reversal cycles.

Abstract: A machine for flash-butt welding of rails, incorporates two tong-type clamping devices made in the form of two two-arm levers carried by a common central axle with insulation from each other and capable of being displaced along the axle relative to each other by two flashing-upsetting hydraulic cylinders connecting them and having bimetal current-carrying rods. Each of the two-arm levers is hinged at one end to the rod or the clamping hydraulic cylinder case, respectively, and the other end is fitted with the clamping and current-carrying jaws. Two welding transformers built into the hollow two-arm levers of one of the two tong-type clamps are joined by current-carrying jumpers through the current-carrying part of the rods of the flashing-upsetting hydraulic cylinders to the current-carrying clamping jaws. A clamping hydraulic cylinder is made with a hydraulic intensifier built into its rod.

Abstract: A method and apparatus is provided for forming an elongated solder joint between two soldered substrates of an electronic module by applying a controlled separating force between the two soldered substrates during and/or after heating of the module. The solder joints are plasticized, preferably to the molten state above the liquidus temperature, and are thereby stretched and the module is then cooled to solidify the stretched joints. An apparatus and method are provided which preferably uses a vacuum device as the separating force to stretch the existing solder joints to the desired solder height and configuration which is preferably an hour-glass shape.

Abstract: A device is provided for stretching solder interconnection joints between two substrates of an electronic module. The device employs an expandable metal to exert a separating (stretching) force to the two substrates whereby a lifting rod attached to a clamping bridge is cause to move upwards by expansion of the expandable metal raising a first substrate clamped thereto. A lifting bridge in connection with the clamping bridge is caused to move downward to maintain the lifting bridge in contact with the second substrate being interconnected to the first substrate.

Abstract: Apparatus and method is provided for separating electrical connections, such as, solder connections, between two surfaces in which electrical connections are relatively weak and thus can be readily separated. The preferred application of the disclosed process and apparatus is its use in separating semiconductor devices from its device carrier after the devices have been through burn-in tests. The unique process and apparatus allows multiple uses of device carrier for testing and/or burning-in devices.

Abstract: A salvage device facilitates detaching a plurality of components soldered to a plurality of modules used in printed circuit board assemblies. In one embodiment, a salvage device has a component receptacle with a component receiver that is adapted to hold a plurality of detached components. The salvage device also has a module holder attached to the component receptacle. In operation, the module holder suspends a plurality of modules over the component receiver to space the components attached to the modules apart from the component receiver. The salvage device is then placed in an oven to melt the solder contacts that bond the components to the modules. After the solder contacts reach a molten state, the components are preferably separated from the module by vibrating the components and the modules to break the surface tension of the molten solder. The components then fall into the component receiver and are removed from the oven.

Abstract: The invention relates to a method for mechanically removing solder beads (14) from the surface of printed circuit boards (10) directly after they pass through the solder flow during flow soldering of printed circuit boards in a soldering plant. In order to ensure that the solder beads are mechanically removed without damaging the printed circuit boards, the solder beads (14) are mechanically removed by means of at least one jet (50) of cold gas directed onto the surface.

Abstract: Excess solder is removed from an article such as a circuit substrate or electronic component as is often required after separation of a mounted component from a substrate. A metal foil having a surface with micro-roughness is brought in contact with the solder material and heated to thereby melt the solder, allowing it to flow onto the foil surface. The foil, having the molten solder therein, is then withdrawn.

Abstract: The misapplication or misplacement of solder bumps on chips and/or circuit boards presents financially significant waste and cost efficiency problems in the manufacture of electronic components. The present invention describes an article and a process for using the article to more quickly remove such spurious solder during manufacture of components. The present invention may comprise an article for assisting in the removal of solder from a surface comprising: a) a surface layer of textured material which can be wet by molten solder, b) a first thermally conductive layer having a surface which is in thermal contact with said surface layer, and c) preferably a flux which is present on at least one of said surface layer and said thermally conductive layer having a surface in thermal contact with said surface layer. The article may be preferably provided where the first thermally conductive layer comprises a sheet of flexible, thermally conductive metal, especially aluminum.

Abstract: Disclosed is a device for separating components (3, 20), in particular electronic components which are connected to a support such as a circuit board (1) by a fixing material such as solder and can be lifted from the support with the aid of a gripping element (17) under a preloaded force acting in the direction in which the components (3, 20) are to be lifted from the support. A lifting device (13) connected to the gripping element (17) causes the preloaded force to become effective when the fixing material reaches its melting temperature. The lifting device (17) is provided with a retaining member (9, 25, 31, 33) whose melting temperature is equal to or higher than that of the fixing material and which triggers the action of lifting the component (3, 20) when the fusible material melts.

Abstract: Process, apparatus and nozzle device are available for controlling the soldering/and or desoldering of a land grid array (LGA) component and corresponding circuit grid present in the surface of a printed circuit board (PCB). The nozzle device comprises a vacuum cup for supporting the LGA parallel to the PCB, with the LGA and the circuit grids in contact or slightly spaced, a device for directing a continuous flow of an inert hot gas, such as nitrogen, from a gas source against the upper surface of a dielectric body of a component to conduct heat therethrough to melt an underlying LGA, vents for venting the major volume of the hot gas, adjacent the upper surface of the body of the component, and one or more vertical passages for directing a minor volume of the total gas flow from the upper surface of the component around the edges, under and horizontally through the array into a discharge chamber, and out a gas outlet.

Abstract: A device for removal of a semiconductor chip interconnected to a substrate package via solder ball connections, for instance, includes an ultrasonic transducer for providing lateral ultrasonic vibration. A converter is coupled between the ultrasonic transducer and semiconductor chip for converting the lateral ultrasonic vibration to a torsional ultrasonic vibration, wherein the torsional ultrasonic vibration is perpendicular to the lateral ultrasonic vibration. The lateral-to-torsional converter further applies the torsional ultrasonic vibration to the chip for facilitating its removal from the substrate package. A method for removal of a semiconductor chip interconnected to a substrate package is also disclosed.

Abstract: Deformation of a lifting ring of bimetallic structure or memory metal is matched to a solder softening or melting temperature to apply forces to lift a chip from a supporting structure, such as a substrate or multi-chip module, only when the solder connections between the chip and the supporting structure are softened or melted. The temperature of the chip, module and solder connections there between is achieved in a commercially available box oven or belt furnace or the like and results in much reduced internal chip temperatures and thermal gradients within the chip as compared to known hot chip removal processes. Tensile and/or shear forces at solder connections and chip and substrate contacts are much reduced in comparison with known cold chip removal processes. Accordingly, the process is repeatable at will without significant damage to or alteration of electrical characteristics of the chip or substrate.

Abstract: A process of producing small metal bumps includes the steps of simultaneously holding small metal balls on an arrangement baseplate in the positions corresponding to those of electrodes of a semiconductor chip, a film carrier, or a substrate; aligning the small metal balls held on the arrangement baseplate with the electrodes; lightly pressing the small metal balls against the electrodes; to provisionally fix the balls to the electrodes; and pressing the provisionally fixed small metal balls to flatten the pressed surfaces of the small metal balls, and at the same time, to bond the small metal balls to the electrodes.

Abstract: An apparatus comprises (a) at least one heater to heat a printed wiring assembly until solder holding selected electrical components reaches a flow temperature; (b) a presence detector to determine when the printed wiring assembly is properly positioned at a first location after the printed wiring assembly (particularly, the solder holding the electrical components) has been heated by the heater(s); and (c) a vibrator positioned to vibrate a selected portion of the printed wiring board of the printed wiring assembly with a first vibrating intensity for a first time period. The first vibrating intensity and the first time period must be of sufficient strength and duration to detach the selected electrical component(s) from the printed wiring assembly. The presence detector is electrically coupled to the mechanical vibrator to activate the mechanical vibrator when the printed wiring assembly is positioned at the first location.

Abstract: A tool for soldering pin-in-hole electronic circuit components includes a tool plate with a set of via holes corresponding to the holes of a circuit board on which a circuit component is soldered. The board is aligned with the tool plate and hot gas is supplied through the set of plate vias to reflow solder in the board holes. The tool is particularly suitable for use in removing and replacing pinned circuit components. Use of particular gases (e.g., nitrogen) allows soldering to be carried out without the use of flux. Advantages of the tool are that it prevents burning the circuit board and/or unintentionally reflowing other circuit components mounted on the board (by directing hot gas only substantially onto the circuit board's solder-containing holes).

Abstract: A system for removing solder from an area grid array pad by applying a wire mesh to a conductive surface of the area grid array that is covered with solder. Heat is applied to the wire mesh and the conductive surface of the area grid array so that the solder flows from the conductive surface onto the wire mesh. The wire mesh is removed from the conductive surface thereby removing all solder from the conductive surface of the area grid array.

Abstract: Apparatus and method is provided for separating electrical connections, such as, solder connections, between two surfaces in which electrical connections are relatively weak and thus can be readily separated. The preferred application of the disclosed process and apparatus is its use in separating semiconductor devices from its device carrier after the devices have been through burn-in tests. The unique process and apparatus allows multiple uses of device carrier for testing and/or burning-in devices.

Abstract: Multi-chip modules provided with a pin array may, under close scrutiny, display certain defects that may cause reliability problems. The presence of even one such defect necessitates the scrapping of the module. A method of salvaging the module is described, wherein the module is reworked by the method comprising the steps of applying a shearing force against the pins. During which the module is exposed to a temperature at or above that which is necessary for softening the braze material to remove the pins; polishing the surface of the module including the pads; evaporating the new pads; and attaching new pins to the pads.

Abstract: Apparatus and method is provided for separating electrical connections, such as, solder connections, between two surfaces in which electrical connections are relatively weak and thus can be readily separated. The preferred application of the disclosed process and apparatus is its use in separating semiconductor devices from its device carrier after the devices have been through burn-in tests. The unique process and apparatus allows multiple uses of device carrier for testing and/or burning-in devices.

Abstract: The present invention relates generally to a new apparatus and method for removing solid material and liquid material that may contain solid material from a substrate. More particularly, the invention encompasses an apparatus and method for removing molten solder which may contain solid particles and solder balls or columns from a substrate using a unique squeegee. Also, disclosed is a method for removing solder balls or columns from a substrate using a backer having an adhesive thereon.

Abstract: A cost efficient, highly reliable method to remove electronic devices and components from substrates eliminates separate tooling for every substrate and device or component size. The apparatus which implements the method allows for multiple device or component removal simultaneously, or in a single sequential operation, in a nondestructive action in a very low cost environment. A box oven and vacuum system and is used with different device or component and substrate sizes providing a simple, low cost, molten device removal procedure, eliminating the need for thermal monitor build and associated profiling for each product. The apparatus works independently of chip type or size, utilizing universal fixturing, and can be set up to pull multiple devices and/or components in a single run.

Abstract: An apparatus for removing and/or replacing a surface-mounted integrated circuit that includes electrical heating elements disposed in a planar rectangular array and a handle positioning the element array in heat-conductive contact with the legs on the side edges of a surface-mounted integrated circuit. When electrical energy is applied to the heating elements, the elements and the integrated circuit legs are heated so as to liquify the solder joints between the legs and the circuit board pads. An air pad is positioned within the heating element array for grasping and holding the integrated circuit to facilitate lifting of the circuit from the circuit board, or for holding a replacement integrated circuit on the circuit board, when all of the solder joints have been liquified.

Abstract: A reflow apparatus includes a reflow furnace. A transfer device holds and transfers printed circuit boards with to-be-reflowed electronic components thereon from an inlet to an outlet of the furnace within the furnace. A plurality of adjusting/circulating sections separate an ambient gas for heating the printed circuit boards into predetermined temperature regions in the furnace in which the ambient gas is circulated in a heated state. A feed port is formed in the furnace to feed the ambient gas into the furnace under pressure. Residence parts each provided between adjacent adjusting/circulating sections regulate the amount of the ambient gas when the ambient gas, after having been sent to and heated in the adjusting/circulating section adjacent to the feed port, is circulated and sequentially moved to the adjusting/circulating sections at the inlet or the outlet and finally flows out through the inlet or outlet into atmosphere.

Abstract: A reflow miniovens is available for soldering/desoldering of BGA and SMT individual components on a printed circuit board (PCB). The minioven is comprised of an apparatus whose top and side oven walls are configured as a gas delivery head terminating in a detachable nozzle fitted over the component, which gas delivery head provides gas delivery and vacuum application apparatus, and with the oven bottom being the PCB and the component being soldered/desoldered being positioned directly above a preheater placed in a table on which an open frame construction board holder holding the PCB is supported, allowing placement of any surface on the PCB in direct and unobstructed view of the preheater. The nozzle is configured to direct heated gas to the component and to direct exhaust gas to a level above the PCB to avoid heating neighboring components on the PCB.

Abstract: A surface mount device desoldering and removal tool includes a flexible carrier plate and a plurality of heated legs attached to the flexible carrier plate for contacting the leads of an electrical component. The flexible carrier plate is sufficiently flexible so that the flexing of the carrier plate allows the plurality of legs to deflect outward to accommodate electrical components of varying sizes. The plurality of legs are heated by electrical resistance heating elements to melt the solder which connects an electrical component to a circuit board. The legs provide a grip on the leads of the electrical component which allows the removal tool to lift the electrical component from the circuit board when all the solder connections have been melted. The flexible carrier plate is advantageously provided with shoulders which allow the electrical component to be easily removed from the removal tool.

Abstract: A rework process for ball grid array (BGA) packages which allows for reuse of devices that have been removed for lack of integrity of solder interconnections. The process uses a rework tool which comprises a plate including one or more depressions corresponding to the contours of inverted BGA packages. A BGA package to be reworked is placed in a respective depression with what remains of the original solder ball grid facing upward. The residual solder balls are wicked away, thus leaving the BGA package with the pads that the solder balls were attached to being exposed. A stencil with BGA patterns punched into it is then placed over the rework tool and solder paste is screened onto the rework tool so that the solder is deposited on the BGA pads via the openings in the stencil. The entire fixture is then subjected to a reflow process to cause the solder to ball up during this process.

Abstract: A weld bead cutter mechanism continuously planes weld beads projecting from the seam weld zone of an electric seamed steel pipe. The weld bead cutter mechanism fits into an assembly line for manufacturing electric seamed steel pipe right after equipment which continuously molds sheet metal and welds the seam. The weld bead is planed off from the steel pipe by a planing blade, bent by a guide shoe fixed to the planing blade holder, and automatically guided through a groove in a bead guide to a rotary bead chopper. The weld bead is then chopped into small pieces as the rotary bead chopper chops it against a stationary blade. The distance between the planing blade and the rotary bead chopper is minimized by the use of the guide shoe and bead guide, which ensures a stable weld bead movement. The weld bead cutter mechanism operates without requiring manual guidance of the weld bead, which greatly reduces the risk of a labor accident.

Abstract: A TIG welding system for controlling the weld shape for the seal welding of a small pressurization hole in the end plug of nuclear fuel rods. The controlled shape of the seal weld enables improved ultrasonic detection capabilities. The system achieves the desired weld shape by controlling the pressure differential between the interior and exterior volumes of the fuel rod. The weld box pressure is decreased in accordance with Boyle's law while the weld material for sealing the hole is molten. The system uses an output from the weld electronics as an input to a programmable logic controller ("PLC"). After a programmed time delay, the PLC outputs a signal to a solenoid valve to open a "ballast" volume. The expansion of gas from the weld box into the ballast volume causes a sudden drop in pressure to a level below the pressure inside the fuel rod. As a result of this pressure differential, the molten weld material forms a concave weld upon solidification.

Abstract: The invention comprises a method and apparatus for handling the weld bead scarfed from the interior surface of continuous seam welded metal tube or pipe incident to its manufacture. A section of tube of predetermined length is cut from the lead and of the advancing continuous tube, having the scarfed weld bead therein, by a rotary cutter. The speed of the individual section is increased to create a gap between the individual section and the continuous tube, and a scissor mechanism severs the weld bead within the gap. The severed section of weld bead is then conveyed within the associated individual section of tube to a tube accumulation or storage area for removal and disposal.

Abstract: A desoldering wick is made from an elongated strip of woven wire mesh slit from a sheet of woven fabric. The wire mesh is folded longitudinally for forming a ribbon having a width less than the width of the strip and having multiple thicknesses of wire mesh with a plurality of spaces between adjacent layers of mesh. The surface of the wire mesh is wettable by molten solder and may be coated with a solder flux for enhancing wetting. A variety of embodiments have folded woven fabric to make three or more thicknesses of wire mesh and are folded so that both slit edges of the strip are inside of the ribbon. Large area desoldering wicks are in the form a pad with a flat face and at least one edge folded approximately normal to the flat face. A ribbon desoldering wick is mounted in an insulating tube for faciltating holding the wick.

Abstract: A porous metal block for selectively removing solder or braze from a substrate is disclosed. The block comprises a plurality of protrusions which absorb solder or braze through capillary action. The number and dimensions of the protrusions vary depending on the application. Also disclosed is a process for making such a block involving a unique two steps sintering process.

Abstract: A specialized desoldering unit head is provided for the limited purpose of removing high-density solid state electronic components from circuit boards in a single step, without damaging the circuit board. In the typical case of a four-sided component with a row of leads on each side, the unit includes an electrically heated head which fits over the component with a heat-conducting blade fitting over each of the rows on the four sides of the component. The head has depth limiters stop means formed by at least one adjustable screw threaded through at least one laterally extended cross-strap on the head and positioned to engage against the top of the component to limit the lowering of the heated blades relative to the rows of leads so that the heated blades do not touch the circuit board, or even the horizontal portion of the surface-mounted leads of the lead rows, but only mounds of solder which have been applied over the leads to facilitate their heating and the removal of the component.

Abstract: A porous metal block for selectively removing solder or braze from a substrate is disclosed. The block comprises a plurality of protrusions which absorb solder or braze through capillary action. The number and dimensions of the protrusions vary depending on the application. Also disclosed is a process for making such a block involving a unique two steps sintering process.

Abstract: In a preferred embodiment, a cutting tool mountable in a rotatable chuck and having a cylindrical cutting member with a cutting surface orthogonal to the axis of the cutting member. The cutting surface includes at least 8 cutting flutes defined therein. The cutting flutes are rounded at the outer periphery of the cutting surface so as to permit chips to clear the cutting surface as the tool is used.

Abstract: To effect disassembly of components relative to an integrated circuit board, the circuit board and its typical construction, including the soldering of the various components projected through the circuit board, is effected by an anvil, including a plurality of anvil bores, wherein the anvil is heated and each anvil bore is accordingly heated effecting the elimination of the associated soldering joints of each projecting tip of an associated electrical component directed through the circuit board. The apparatus further includes a metallic brush member arranged for securement to an associated heating member or gun to effect the cleaning and removal of solder residue remaining on the circuit board. Further, various anvil sizes are provided to accommodate various circuit board patterns and may be provided in a kit form in a single unitary container.

Abstract: This invention relates to an apparatus and method by which electronic components can be reclaimed from printed circuit boards. In the preferred embodiment, the reclamation system includes a conveyor which grasps the edges of the boards and holds them at an angle so that the component sides of the boards are facing downward. The conveyor carries the boards past infrared panels which heat each board, so that the solder bonding the components to a given board is made to reflow. While the solder is in a reflow state, each board is struck with a tapper, the impact of which has a tendency to dislodge the components. Falling components are caught in bins where they can be collected. In addition, the reclamation system is configured such that a number of operators are able to work in front of the boards passing on the conveyor. Therefore, if the tapper fails to dislodge any components on a given board, an operator can manually remove the components before the board is itself removed from the conveyor.

Abstract: A solder bump stretch device is disclosed for use in mounting an electronic component to a substrate by a plurality of solder bump interconnections that are produced by reflowing preformed solder bumps carried on the component. the device is fastened to the component, which is in turn assembled with the substrate so that the bumps rest upon the substrate in preparation for solder reflow operations. The device comprises a flexible web that overlies the component outer face and is connected to legs that depend about the component. Prior to solder reflow, the web is held by an expendable spacer in a biased position wherein the legs are raised apart from the substrate. During heating to melt the solder bumps, the spacer is expended, releasing the web, whereupon the legs engage the substrte to lift the component relative to the substrate and thereby stretch the molten solder to form elongated interconnections preferably having hourglass configurations.

Abstract: A desoldering wick which comprises a small number (e.g., three) of strands of a thin wire (i.e., having a diameter less than about 0.002") braided together to form a hollow tube which is subsequently flattened. Such a wick is suitable for use in desoldering operations for which the heretofore available products were too large, and provides a more rapid removal of molten solder than is achieved with the prior art products. Methods and apparatus are also provided which enable the manufacture of desoldering wicks comprising fewer strands of wire and/or wire of a substantially smaller diameter than has heretofore been possible. By modification of conventional apparatus to reduce the substantial drag on the wire strands heretofore encountered during the braiding operation, it is now possible to prepare wicks with thicknesses on the order of about 0.008" from wire having a substantially smaller diameter (i.e., less than 0.002") than was previously feasible.

Abstract: An effective, convenient, economical and safe system for installing and removing multi-sided gull-wing semiconductor devices from circuit boards without damaging the semiconductor device is provided. The solder removal system is formed by the combination of a surmo-multi-sided wick formed from welded braids and a solder removal gun that has been adapted with a corresponding multi-sided tip face with vacuum capability. An apparatus and process of using such apparatus thereof to produce the multi-sided shape surmo-wick used in the solder removal system are also provided.

Abstract: A device for cleaning and servicing a weld site about the periphery of a extending control rod drive mechanism and adapter tube including a housing adapted to be positioned adjacent to and rotated about the periphery of the control rod drive mechanism and a carriage assembly including an inner and outer portion reciprocably received within the housing is provided. Mounted within the housing is a first drive motor for driving a threaded lead screw rotatably mounted within the housing with an internally threaded follower secured to the carriage assembly and mating with the threaded lead screw for reciprocating the carriage assembly relative to the housing in a direction substantially parallel to the control rod drive mechanism.

Abstract: A desoldering material with an opening or window shaped so that the base of an electronic component can fit inside the opening while the desoldering material simultaneously contacts all solder joints which bond the component's outer leads to pads on a surface. A first adhesive secures the base to the surface, a second adhesive secures a retraction device to the base, the first adhesive is heated and softened without softening the second adhesive, and the retraction device removes the desoldered component from the surface. The invention is well suited to removing tape-automated-bonded integrated circuits adhesively attached to high density multichip module substrates.

Abstract: A device having a plurality of columnar structures comprised of a solderable metal disposed on a supporting base is used to remove solder from a substrate surface. Capillary action takes place in the area between the columns, thus removing the solder from the substrate surface. The present invention may be fabricated by forming columnar structures on the supporting base through mask openings or by etching a solderable metal layer into columnar structures. A standoff may be built into the device to prevent solder residue from remaining on the substrate surface between solder pads and to allow a controllable amount of solder to be left on the substrate surface.