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 invention provides a device for moving an object by means of thermal change in shape or volume, such that the object is moved when a predetermined process temperature has been reached. Preferably the device can be used in a soldering system on a printed circuit board. The advantage of the invention lies in a temperature-controlled movement of the object with a high-level precision that, for example, ensures a very sparing unsoldering.

Abstract: In one aspect, a device for attaching a component to a circuit board is provided, comprising a circuit board held in a holder and a contact heater that heats the component on the circuit board by contact and by conducting heat through the component. In a further aspect, the contact heater is in a wand which is manually moved onto the component. In another aspect, the invention provides a method for attaching a component to a circuit board, comprising the steps of gripping the component with a contact heater; placing the component on the circuit board; and heating the component on the circuit board by contact, wherein heat conducted through the component melts solder under the component and attaches the component to the circuit board.

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 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 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 electronics device has unpackaged chips or other small components mounted on a carrier and wire-bonded to carrier wiring traces. The rear chip faces have a layer of adhesive which overlies a layer of solder or other fusible material, and which adheres to a pad area of the carrier. To replace a chip, its solder layer is melted, and the chip and adhesive are pulled off. Reapplying an adhesive layer allows a new chip to be mounted on the carrier and bonded to the traces.

Abstract: An apparatus for soldering/unsoldering SMD components comprising a heating nozzle which both permits direct heating of the component by contact with a hot nozzle bottom and directs a stream of hot gas onto the leads of the components. The nozzle bottom is preferably made of highly thermoconductive material and the hot gas stream is directed onto the leads by means of at least one outlet slot in the nozzle bottom adjacent the nozzle wall. The nozzle further comprises a centered suction means for positioning/removing the component.

Abstract: A method in which the interface at which two components are bonded together, by a bonding material that has a lower melting temperature than the material from which the components are made, is heated to the melting temperature of the bonding material, allowing the components to be separated without cutting any of the interface material.

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: 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: 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 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 new rework process for semiconductor chips mounted in a flip chip configuration, via solder balls, on an organic substrate is disclosed.

Abstract: A solder ball removal tool uses ultrasonic vibrations to remove specific solder balls from high density chips, substrate solder ball terminal connections, card or board solder ball connections, or other solder ball array for the purpose of customizing the electrical functionality of a module. The tool also allows for the removal of damaged or defective solder balls for the purpose of replacement with defect free solder balls.

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: The use of a liquid nitrogen (LN.sub.2) bath to produce thermal stress between an aluminum heat sink and a silicon circuit board by deep cooling, makes it possible to separate each from the other product undamaged. This allows repair or replacement of the silicon substrate in a very short time with very little turn around time.

Abstract: Process and nozzle device for the soldering and/or desoldering of a land grid array (LGA) component and a corresponding circuit grid present on the surface of a printed circuit board (PCB). The nozzle device comprises a vacuum for supporting the LGA parallel to the PCB, with array contact, a fixed orifice gap for directing hot gas horizontally through the array, and a gas outlet. Uniform circulation of the hot gas is continued to produce uniform, simultaneous melting of the solder array to permit bonding to or desoldering from the circuit array of the PCB while supporting the component parallel to the PCB.

Abstract: An apparatus for removing an electronic device from a printed circuit board includes a board support for supporting the printed circuit board with the first main surface thereof directed upwardly and for vertically moving the printed circuit board; a lower heating device for applying heat from the second main surface side of the printed circuit board; an upper heating device for applying heat from the first main surface side of the printed circuit board; a withdrawal device disposed on the first main surface side of the printed circuit board for applying a force to withdraw the electronic device from the printed circuit board, the withdrawal device detecting the withdrawal of the electronic device; and a solder elimination device disposed on the first main surface side of the printed circuit board, the solder elimination device comprising a hood for covering that portion of the printed circuit board where the electronic device is mounted, and a pressure control device for increasing or decreasing a pressure w

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: In a process for separating overlapping sheet metal panels, which are welded together by a series of spot-welds, the portion of each spot-weld in one of the panels is removed by drilling or milling after which pressure is applied by means of a tool, driven by a pneumatic hammer device, to the remaining portion of the spot-weld in the other panel forcing the other panel away from the one panel and separating of the panels without substantial damage to the panels. Alternatively, a hole saw may be used to separate the spot-weld from the one panel before pressure is applied to the spot-weld to separate the panels.

Abstract: A clamp structure is provided for removably rigid attachment to a fluid flow nipple projecting and opening outwardly from a wall portion of an end tank of a heat exchanger and structure is carried by the clamp structure for rigidly attaching a vibratory thereto, whereby the vibrator may be utilized to vibrate the clamp structure and in turn vibrate the fluid flow nipple and the associated end wall tank while heat is applied between the marginal edges of the end wall tank enjoying a solder seam with corresponding marginal edges of a heat exchanger core header plate, the vibration of the header tank during the unsoldering operation preventing a melted solder seam or joint being reformed behind a torch being moved along the solder joint or seam to melt the same.

Abstract: A method for removing an individual surface mounted electrical component from a printed circuit board retaining a plurality of other components. The individual component has a plurality of leads connected to circuitry on said board by a connection alloy comprising at least two constituent metals and having a given melting point less than that of either of said constituent metals. The method includes the steps of obtaining a removal alloy composed of a plurality of constituent metals and having a particular melting point below the given melting point; heating the removal alloy to a temperature greater than the particular melting point but below the given melting point so as to produce a molten state thereof; contacting the connection alloy on all of the leads with the molten removal alloy and causing thereby a reaction producing a molten state for the connection alloy; and separating the individual component from the printed circuit board while retaining thereon the other components.

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 method and apparatus for removing wires bonded between chip contact pads and substrate contact pads using an alternating fluid flow is described. The fluid flow is preferably air. A nozzle having a plurality of air jets within a chip accommodating cavity is disposed over the chip to enclose the chip contact pads, the substrate contact pads and the wires bonded therebetween. Air is forced through the plurality of jets to cause an alternating clockwise and counter clockwise air flow which bends the plurality of wires back and forth until they fatigue at the contact points to the chip contact pads in a substrate contact pads which results in the wires being substantially simultaneously severed therefrom. The nozzle has an aperture out through which the air escapes carrying the severed wires therewith for collection in a filter.

Abstract: A component installation/removal tweezer-type handpiece having two arms and a tinnable or nontinnable tip including a pair of legs respectively removably mounted with respect to the arms and a plurality of serially connected bands attached to the first and second legs such that an opening is formed within the serially connected bands so that the bands are adapted, upon closure of the tweezer-type handpiece, to clamp the terminals of an electronic component or the like and transmit heat to the terminals. In another embodiment a tweezer-type or probe-type handpiece includes a tinnable or nontinnable tip having first and second legs and one or more bands extending between the legs whereby the band(s) is adapted to transfer heat to terminals associated with an electronic component. In all embodiments of the invention the tips may be provided with a variety of sheathing or overlayer combinations to achieve a variety of application requirements.

Abstract: A stacked packaging assembly for a plurality of integrated circuit devices employs a web of flexible interconnect material folded into a `layered` arrangement of parallel web fingers onto which a plurality of integrated circuit devices are surface-mounted. The leads of the integrated circuit devices are attached to interconnect links of the flexible interconnect web. A plurality of heat sink plates are interleaved with the folded web fingers of the stack, so as to engage the integrated circuit devices mounted on the web fingers. The heat sink plates are retained by thermally conductive spacer blocks along their edges. The spacer blocks are clamped together in a compact laminate structure, so as to form a rigid support which relieves mechanical stresses at the folds of the web fingers.

Abstract: A chip removal method and apparatus for use with a robotic unit. The chip removal apparatus includes a heated center quill and a soldering unit which cooperate together with a chip removal tool for simultaneously disabling the bonding materials securing a chip to a printed circuit board. The method permits the fine pitch chip device to be removed from the printed circuit board substantially intact for subsequent testing purposes.

Abstract: An ultrasonic adhesion/dehesion monitoring apparatus for monitoring the quality and/or adhesion/dehesion between first and second substrates comprising: (a) an ultrasonic source for transmitting ultrasonic energy to at least first and second substrates; (b) acoustic transducer means proximate to the ultrasonic source and/or the substrates; and (c) monitor means coupled to the acoustic transducer means for monitoring the ultrasonic signal from the ultrasonic source. Also disclosed is a method for monitoring the quality and/or adhesion/dehesion between first and second substrates in the ultrasonic adhesion/dehesion monitoring apparatus.

Abstract: Method and apparatus for vertically removing semiconductor integrated circuits (91) from high density multichip hybrid microcircuits without interfering with close proximity neighboring devices. An integrated circuit (91) is vertically removed by simultaneously applying tensile and torsional forces thereto. By using the present invention to transfer some of the tensile force torsionally, high density multilayer interconnect substrates (93) survive the rework process without damage. The present invention employs techniques which allow for accurate and repeatable removal of closely spaced integrated circuit devices. Removal of an integrated circuit (91) is accomplished by bonding a special thermode device (70, 70') directly to the integrated circuit (91) using a thermoset, or a thermoplastic, die attach material (90). Once the thermode (70, 70') has been attached, tensile and torsional forces are applied to the integrated circuit (91) through the attached thermode (70, 70').

Abstract: A method of removing components bonded to a substrate without damaging either the component-to-be-removed or adjacent components involves bonding a lifting member to an exposed surface of a component-to-be-removed with a bonding layer whose yielding temperature is above the yielding temperature of the bonding layer which bonds the component-to-be-removed to the substrate and then pulling the lifting member under conditions which cause the bond between the component and the substrate to yield. This component removal process enables post removal failure analysis to be performed on a faulty component and also allows a removed good component to be reused by preventing damage to the component being removed.

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: 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 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.

Abstract: A robotically controlled pick-uo to tool (11) is modified by connecting to it a load cell (26) that generates a signal indicative of stress on the pick-up tool. The pick-up tool is directed toward a chip (12) to be removed and movement is stopped when the load cell generates a first signal indicative of a first level of stress. In addition to stopping movement of the pick-up tool, the first signal actuates heating of the tool to a temperature sufficient to melt the solder (13) bonding the chip to the substrate (14). The melting of the solder bonds (13) results in a reduction of stress on the tool, which causes the load cell (26) to generate a signal indicative of the second level of stress. The second signal actuates the vacuum of the pick-up tool to cause adhesion of the chip to the pick-up tool and also initiates movement of the pick-up tool so as remove the chip from the substrate.

Abstract: A method for winding a soft-magnetic ribbon to form a self-contained magnetic core using a winding arbor includes the step of, after the ribbon has been wound on the arbor, holding the free end of the ribbon to the preceding turn by spot welds, disposed in general alignment along a center of the ribbon. The free end of the ribbon may be tapered, so that projecting corners are avoided. By making the spot welds substantially in the center of the ribbon, the formation of eddy currents, which may occur if the spot weld accidentally connected two adjacent turns of the ribbon, are avoided. A similar method may be used to releasably attach the beginning of the ribbon to the arbor, with the spot welds then being broken when the core is removed from the arbor. The method is particularly suited for winding a ribbon consisting of amorphous soft-magnetic material.

Abstract: A tool for repairing an improperly positioned surface mounted component on the printed circuit board consisting of a body portion with a pair of legs positioned relative to the component mounting area on the printed circuit board with an included vacuum mechanism used to seize the component and reposition it against locating cams included in a pair of vertical legs.

Abstract: A solder well configured to abut and enclose the though hole pattern on a printed circuit board to allow the reflow of solder and removal of a multipin electronic component without affecting the integrity of adjacent solder joints of components disposed within or adjacent the through hole pattern.

Abstract: A method and apparatus are described for the removal of solder mounted surface mount electronic components which includes the removal of old solder, broken leads, and the electronic component without damaging other devices on the substrate. A desoldering braid is shaped to cover each of the electronic component's outer lead bonds without contacting the component's base. The desoldering braid is heated and brought in contact with the bonds until the solder flows into the desoldering braid and any broken outer leads attach to the desoldering braid. Upon removal of the desoldering braid the electronic component can be lifted off the surface. The desoldered solder joints will contain a thin uniform coating of solder less than approximately 50 micro inches thick. This allows for removal and replacement of solder mounted electronic components with leads on center lines spaced less than 0.020 inches.

Abstract: A tool adapted to facilitate the removal of elements such as pin grid arrays, pin grid array sockets, chip carriers, and chip carrier sockets which have been soldered into plated through holes or similar elements of printed wiring cards. A platform is provided mounting two pivotable arms which are used to grip onto the element to be removed while a number of spring loaded posts are compressed to provide connection to the printed wiring card on which the element to be removed is attached. The entire assembly is then placed in a high temperature environment causing the solder to melt at which time the compressed springs, associated with the posts, effectively expand withdrawing the element from the printed wiring card.

Abstract: A solder bridge between leads of a microelectronic circuit is removed by projecting a laser beam onto the solder bridge with sufficient power to cause the solder forming the bridge to melt and to flow onto a wicking tool placed into contact with the solder bridge. The wicking tool is removed during the heating to remove the solder and debridge the leads. Microelectronic leads having a width of the order of 4 mils and a pitch of the order of 8 mils may be debridged easily using the invention.

Abstract: A technique is provided for desoldering circuit components employing a desoldering aid that fits like a cap on a standard size rectangular circuit component. The aid has a rectangular top of high thermal conductivity metal substantially the same size as the circuit component. At least a pair of integral sides along opposite edges of the top are bent normal to the top and are not further apart than the outside of the electrical leads on the opposite sides of the circuit component for good thermal contact therewith. The depth of the inside of the box is greater than the height of the top of the component so that there is no contact between the top of the box and the top of the component. The top of the box over the component is heated sufficiently to melt solder on the electrical leads. The box and component can then be lifted together from the printed circuit board.

Abstract: Method for reflow soldering respectively desoldering of circuit boards by using infrared radiation from radiator groups in a furnace. The circuit boards are introduced into the furnace on a timed belt or work piece carrier and maintained motionless during the prewarming, soldering respectively desoldering and cooling down phase. For prewarming for a first given time the radiator groups are operated with reduced operating current. For reflow soldering respectively desoldering the operating current of the radiator groups is switched for a second given time to a maaximum given stage and subsequently turned off completely. The soldered respectively desoldered circuit boards are cooled in a laminar air stream from ventilators for drawing off the solder vapors; the ventilators are initially operated with reduced number of rpms until the solder solidifies and then at the maximum number of rpms. Subsequently, the circuit boards are moved out of the furnace.

Abstract: Leaded and leadless surface mounted devices are removed from or attached to a printed circuit board at various locations, without interfering with or adversely affecting other chips on the printed circuit board. The method of removal involves placing a tool on the substrate, comprising a rigid plate containing a hole, and a hollow tube extending beneath the hole from the rigid plate to the substrate. In this way a surface mounted device to be removed may be surrounded completely by the hollow tube, without encompassing adjacent chips. When heat is directed through the hole in the rigid plate and through the hollow tube to the surface mounted device, the soldered connections attaching the surface mounted device to the board may be melted. A disconnecting means is utilized to remove the surface mounted device from the substrate at the moment the soldered connections are melted or, in the case of non-eutectic solder, changed to a plastic phase.

Abstract: A convection heat attachment and removal system for surface mounted assemblies is disclosed which uses a flow of heated gas to heat and melt solder contacts between surface mounted components and printed circuit boards. The system protects components adjacent to the workpiece by confining the flow of hot gas within a nozzle conduit which encompasses the workpiece. The system also protects the workpiece from overheating and thermal shock by shielding the workpiece from direct incidence of hot gas and by cooling the top surface of the workpiece with cool air. Relative positioning of the workpiece, the printed circuit board and the source of convection heat is accomplished by an arm mechanism as well as an X-Y table. The positioning means in this system are designed to accommodate a method of precise positioning disclosed herein. Convenient physical and visual access is provided to the workpiece and its location on the printed circuit board at any time during positioning.

Abstract: A nozzle device is adjustably positionable over a component which is disposed on a substrate, for registering relatively precisely against the component relative to the substrate for delivering a flow of uniformly heated air. The heated air is directed to the sides of the component to melt solder associated with terminals thereon. A series of changeable nozzles can be used for various component and terminal configurations and can be moved into or out of registry with the component. A vacuum apparatus can be provided for contacting the component to remove the component from the substrate. Notched end portions of inwardly projecting walls on the nozzle provide accurate registration with upper edges of the component, and permit accurate spacing of a skirt portion of the device relatively evenly from the substrate and relatively evenly from the sidewalls of the component.

Abstract: A solder reflow machine for removing and replacing electronic components of the pin-grid array type having a large number of leads soldered into a very densely populated printed circuit board. The machine utilizes a heat-transfer liquid and a vacuum to remove the component from the board. The printed circuit board is positioned with the component facing downwardly. A tank containing the heat-transfer liquid is located below the printed circuit board. The apparatus includes a solder reflow head which has a component-engaging vacuum plate with a central opening that is in communication with a vacuum source through a pipe which is pulled downwardly to remove the component. The component is surrounded by a wall in combination with the bottom of the printed circuit board and seals off the liquid flow path.