Abstract: A method and apparatus are disclosed for releasing solder spheres during the locating and/or placing of a pattern of conductive preforms 32 on a respective pattern of electronic pads 14 on a receiving substrate 12 for such uses as a Ball Grid Array component 24. The release mechanisms are of either compliant mechanical 11, vibratory 90, air pressure 100 or 120, or sound pressure waves 140. Additionally, a method and apparatus is disclosed for the electrical inspection for presence or absence of the complete pattern of conductive preforms.

Abstract: For reflow soldering, radiant heating is applied to one surface of a printed circuit board on which electronic components are placed and onto which cream solder is supplied and at the same time hot air is blown locally and roughly perpendicular to to-be-connected points on said one surface of the printed circuit board. This reflow method permits secure soldering even if the hot air is set at a temperature not exceeding the heat resistance of the electronic components, which is possilbe because of its combination with the radiant heat. Moreover, this reflow method can permit soldering in such a manner that only the to-be-connected points are heated selectively, because the hot air is blown locally and roughly perpendicular to the points to be connected. Thus, this reflow method prevents heat damage to other sections than the to-be-connected points and ensures that the solder at the to-be-connected points is melted.

Abstract: A conductive paste is loaded in circular holes made in a reinforcing film of a carrier tape which includes a film substrate and the reinforcing film, followed by applying a heat treatment to the conductive paste to form projecting electrodes consisting of solder. Then, the reinforcing film is peeled off to permit the projecting electrode to project from the film substrate.

Abstract: A method and apparatus for retaining heat at a pin-in-hole rework site on a printed circuit board during solder fountain rework of the board. A preheated heat retention plate is attached to the rework side of the printed circuit board. The heat retention plate covers a substantial portion of the board surface. During rework of the printed circuit board, the heat retention plate minimizes the temperature gradient between the rework site of the printed circuit board and the remainder of the printed circuit board. During the rework, the heat retention plate can be heated by an active heater in order to maintain a constant temperature gradient between the rework site of the board and the remainder of the board. By minimizing the escape of heat from the rework site, the number of solder cycles required to rework the board is decreased, resulting in reduced board rework times and increased board longevity.

Abstract: A method of applying a matching layer to a transducer includes placing the transducer on a fixture and covering the transducer with a stencil so that an opening in the stencil allows access to a metal-coated, piezoelectric surface of the transducer, and so that the stencil is affixed to the transducer surface. A roughly cylindrically shaped bead of epoxy is extruded onto the stencil at a predetermined distance from the opening, and a blade is positioned upstanding relative to the transducer surface and located so that the bead lies between the blade and the opening. The fixture is moved laterally so that the blade rolls the bead across the exposed transducer surface to form a layer of epoxy thereon. The fixture can then be moved back in the opposite direction to its initial position if desired. The assembly can also be subjected to a vacuum before the fixture is returned to its initial position. If desired, the fixture can be designed to vibrate during movement.

Abstract: A method and apparatus are disclosed for releasing solder spheres during the locating and/or placing of a pattern of conductive preforms 32 on a respective pattern of electronic pads 14 on a receiving substrate 12 for such uses as a Ball Grid Array component 24. The release mechanisms are of either compliant mechanical 11, vibratory 90, air pressure 100 or 120, or sound pressure waves 140. Additionally, a method and apparatus is disclosed for the electrical inspection for presence or absence of the complete pattern of conductive preforms.

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: An apparatus used in a process for supporting a printed circuit board during a wave soldering operation including a frame with a frame opening in which a surface of the frame supports the board and also serves as a reference surface for vertically positioning the board above the solder pool. The board is secured against the reference surface with spring loaded clamps. Stiffeners preferably being an aluminum extrusion having a Tee or angle cross section is mounted along the outside edge of the reference surface of the frame and has a second reference surface facing in a direction opposite the reference surface of the frame. The second reference surface on the extrusion is accessible for support by a slide rail so that the height of the reference surface of the frame above the surface of the pool is independent of the thickness of the board or frame.

Abstract: An apparatus and method for connecting together first and second printed circuit boards 10/20 (PCBs), wherein one or both of the PCBs is a flex circuit. The method includes overlapping the two PCBs such that their respective matching circuit trace arrays 12/22 face each other and are separated by a small predetermined distance K, and then introducing molten solder 30 proximate an overlapping PCB edge 18, such as by wave soldering, so as to urge capillation of the molten solder between the two PCBs, thereby forming solder joints operatively connecting together the two circuit trace arrays.

Abstract: A method by which a conventional circuit trace (14) is modified with a layer (16) of high-conductivity solder alloy to yield a high-current circuit trace (12) for high-current routing on a substrate (10). The method generally entails the use of a solder composition that contains a dispersion of metal particles (18) in a solder alloy (20). The metal particles (18) are selected on the basis of having a higher electrical conductivity than the solder alloy (20), and are present in sufficient amounts so that the electrical conductivity of the solder composition is significantly higher than that of the solder alloy (20). The solder composition is deposited on a conductor (14), and then reflowed to form a conductive layer (16) on the conductor (14). The metal particles (18) remain as a discrete dispersion within the conductive layer (16) in order to suitably promote the conductivity of the layer (16).

Abstract: The precise solder paste application process makes use of mask registration apertures that are formed in the printed circuit board and that are adapted to receive a component solder paste mask that conforms to the conductor pattern of the component to be replaced. The component solder paste mask comprises a mask that has formed therein apertures that correspond to the pattern of solder paste that is to be applied to the printed circuit board surface mount pads to correspond to the conductors of the component. The component solder paste mask includes registration features that mate with the registration apertures formed in the printed circuit board to thereby ensure precise placement of the component solder paste mask over the area of the printed circuit board that receives the replacement component.

Abstract: A wave solder pallet having a first side that is adapted to receive a printed circuit board and a plurality of through holes or apertures that will allow solder to be transmitted through to selected regions on the printed circuit board. The surface of the base plate that is positioned adjacent the solder wave has channels formed therein, the channels being tapered inwardly so that the overall volume of the channel is greatest at the periphery of the pallet. The increased volume of the channel reduces the pressure effect of the solder wave as it contacts the pallet at the periphery thereby reducing the amount of solder that is splashed over the pallet. The tapering of the channel uniformly increases the pressure so that the pressure effect of the solder wave is increased when it travels through the apertures.

Abstract: A molded selective solder pallet and a method for fabricating a molded selective solder pallet for use in a wave soldering process to selectively affix solder to an area of a circuit board having an electronic component thereon. The selective solder pallet according to the present invention includes a mold base configured having an aperture formed through its cross-section. A high temperature casting material is molded within the mold base and configured to have at least one recess and at least one solder flow opening. A high temperature silicone casting material may be employed as the high temperature casting material.

Abstract: A transport head (10) and a method for transporting flux and solder balls (50) to locations for bonding pads (46) on a workpiece (44). To transfer flux, a first pattern definition mask (12) is attached to the transport head (10) and allows selector pins (64) to fully extend and receive flux for transport to the bonding pads (46) on the substrate (44). To transfer the solder balls (50), pattern definition mask (12) attached to the transport head (10) defines locations that are to be populated with the solder balls (50). The transport head (10) transfers the solder balls (50) to the bonding pads (46) of the substrate (44).

Abstract: Disclosed are methods and apparatuses for forming solder bumps on integrated circuit chips (and other similar circuitized units) and apparatuses. A screening stencil is laid over the surface of the substrate and solder paste material is deposited into the stencil's apertures with a screening blade. The stencil is placed in such a manner that each of its apertures is positioned over a substrate pad, upon which a solder bump is to be formed. Next, a flat pressure plate is laid over the exposed top surface of the stencil, which creates a fully enclosed, or "captured", cell of solder paste within each stencil aperture. Then, with the stencil and plate remaining in place on top of the substrate, the substrate is heated to a temperature sufficient to reflow the solder paste material. After reflow, the substrate is cooled, and the pressure plate and stencil are thereafter removed, leaving solder bumps on the substrate.

Abstract: A method and apparatus is disclosed for applying solder to a substrate which has a predetermined pattern of receiving pads thereon and forming solder balls from the applied solder. A conveyor is provided having a support member and a continuous metering member. The metering member has openings thereon arranged in the same preselected pattern as the solder receiving pads on the substrate. The substrate is moved into contact with the support member and the metering member, the openings in the metering member being in alignment with the solder receiving pads of the substrate. A container of solder is provided which supplies solder to the openings. The solder may be in liquid form, or in paste form, or in the form of solid solder balls. The applied solder, if in the form of paste or solid balls is melted. Thereafter, the solder is solidified on the pads to form solder balls, and the substrate is discharged from the conveyor with the solidified solder balls thereon.

Abstract: The present invention provides a vertical card connector capable of preventing an undesirable flow of melted solder which destroys proper contacts and of removing a corrosion-causing acid gas. The vertical card connector includes an insulating housing with a plurality of contact terminals and a heat-resisting insulating resin film covering the bottom surface of the housing. The solder tail of the contact is inserted into a corresponding plated through hole and soldered there. The film prevents melted solder from flowing past the solder tail toward a contact beam of the contact at the time of soldering. Gas produced from the solder escapes through the gap between the circuit board and the bottom of the housing.

Abstract: A fixture for supporting printed circuit (PC) boards during wave soldering includes a rigid frame having a ledge formed along the inner perimeter of the frame. The ledge supports a PC board along a peripheral portion of the board. Channels are formed atop the frame for receiving slidably removable clamps. The fixture further includes a slidably removable rail coupled to the frame along its channels. The rail includes a ledge that is coplanar with the ledge of the frame. The rail can be adjusted to provide support for smaller PC boards. A drop-plate component includes a recessed area for receiving a PC board, and depressed regions for masking components on the board. Openings formed in the drop-plate expose desired areas of the board for soldering. The drop-plate, loaded with a PC board, fits into the frame along the ledges of the frame and/or the rail for a wave soldering operation.

Abstract: A shield (50) for use in wave soldering processes to selectively affix solder to an area of circuit board (20), having one or more electronic components (21) on the solder side of the board, is disclosed. Shield (50) includes a generally planar base member (51) of low thermal conductivity which forms the foundation of shield (50). Marginally disposed registration ridges (54) are formed on the upper surface (52). Registration ridges (54) serve to hold circuit board (20) against shield (50) in a fixed position. Ridges (54) are positioned to closely receive the peripheral edges of circuit board (20). One or more solder flow openings (56) are formed through base member (51) extending from upper side (52) to lower side (53). Solder flow openings (56) are positioned to align with the selected areas of circuit board (20) to which solder is to be affixed. One or more recesses (55) are provided in the upper surface (52) of base member (51) to receive and shield electronic components (21).

Abstract: A shield (50) for use in wave soldering processes to selectively affix solder to an area of circuit board (20), having one or more electronic components (21) on the solder side of the board, is disclosed. Shield (50) includes a generally planar base member (51) of low thermal conductivity which forms the foundation of shield (50). Marginally disposed registration ridges (54) are formed on the upper surface (52). Registration ridges (54) serve to hold circuit board (20) against shield (50) in a fixed position. Ridges (54) are positioned to closely receive the peripheral edges of circuit board (20). One or more solder flow openings (56) are formed through base member (51) extending from upper side (52) to lower side (53). Solder flow openings (56) are positioned to align with the selected areas of circuit board (20) to which solder is to be affixed. One or more recesses (55) are provided in the upper surface (52) of base member (51) to receive and shield electronic components (21).

Abstract: A mask for printing solder paste includes a mask plate, and first mask holes which are formed in the mask plate and have a first size, and second mask holes which are formed in the mask plate and have a second size smaller than the first size. The mask plate has a first region having the first mask holes, and a second region having the second mask holes. The mask plate has a first thickness in the first region, and a second thickness in the second region. The second thickness is smaller than the first thickness.

Abstract: An electrical connector comprises a housing and terminals mounted therein, the terminals comprising contact tails for soldered connection to a printed circuit board. The contact tails have sealing material deposited thereon for sealing between the contact tail and housing to prevent solder and flux wicking onto contact sections of the terminals. The concept also advantageously provides sealing of the connector from the environment, whilst using minimal quantities of sealing material and having very small sealing surfaces for increased reliability thereof.

Abstract: Stencils having enhanced wear-resistance consisting of a metal body, preferably fabricated from stainless steel, having a first major surface and a second major surface and a plurality of apertures extending through the metal body from the first major surface to the second major surface, and a diamond coating which is preferably applied to at least the top surface of the metal body, and to the side walls of the plurality of apertures. Such stencils are particularly useful for positioning solder paste in predetermined areas on contact pads of printing wiring boards. The diamond coating is preferably deposited on the stencil surfaces from a vapor phase of carbon-containing gases. By applying the diamond coating to the top and side wall surfaces of the stencil, improved wear-resistance is achieved, resulting in increased service life for the stencils.

Abstract: An apparatus for facilitating wave solder treatment and other handling of a circuit component during manufacture of the circuit component having first areas configured for wave solder treatment and second areas not configured for wave solder treatment. The apparatus comprises a substantially rigid frame generally symmetrical about a plane and defining an opening which traverses the frame intermediate a first side and a second side. The apparatus further comprises a masking member affixed to the frame and defining a plurality of apertures traversing the masking member to the opening in the frame. The apparatus also comprises a holding device for holding the circuit component in an operational location in fixed relation with the masking member and with the frame during wave solder treatment. Each of the first areas of the circuit component is substantially in register with an aperture of the masking member when the circuit component is in the operational location.

Abstract: Damage to the pins and ceramic body of pin grid array type semiconductor device assemblies is avoided by providing ceramic bushings in the pin-receiving holes of a boat transport. The bushings elevate the package body above the platform surface of the boat, and also alleviate problems associated with unequal thermal expansion of the metal boat and the ceramic package. In an alternate embodiment, a ceramic insert formed as a square ring encompassing an area roughly equivalent to the area of the package body is provided with holes for receiving the pins, and the boat transport has a cavity for receiving and retaining the ceramic insert.

Abstract: This invention relates to an apparatus for coating solder on the outer leads of TAB-type semiconductor devices. The solder coating apparatus comprises a solder tank accommodating a heater, a discharge tank having an open top and a solder inlet opening at a lower part thereof, a square pillar having a top of substantially the same or slightly greater size than a semiconductor element and arranged inside the discharge tank and projecting beyond the open top thereof, and a solder pressure feed screw near the inlet opening of the discharge tank. A film carrying semiconductor elements is intermittently stopped when one of the semiconductor elements arrives above the square pillar. Molten solder is discharged from gaps between the inner walls of the discharge tank and the square pillar onto the outer leads of the semiconductor element positioned over the pillar.

Abstract: A printed circuit board handle is disclosed for use with a printed circuit board. The printed circuit board handle includes a flange that extends for the length of the handle and is mounted to the printed circuit board. Two ribs protrude from the side of the flange that is adjacent to the printed circuit board and extend for the length of the handle. The ribs contact the printed circuit board in such a manner as to separate the body of the flange from the printed circuit board and thereby prevent the capillary action that causes entrapment of flux between the flange and the printed circuit board, during the wave soldering process.

Abstract: Apparatus for coating the endmost threaded section of a pipe with corrosion resistant powder coating material by rotating the pipe and spraying the section to be coated with electrostatically charged, air-entrained powder through two stationary nozzles, one of which is directed at the section to be coated, and the other of which is directed at the chamfered end of the pipe. To prevent overspray of the powder from contacting the pipe adjacent to the area to be coated, a pair of air nozzles are directed at the area of the pipe adjacent to the area to be coated.

Abstract: An electronically controlled mask shield for a wave soldering machine is disclosed which can be positioned to shield gold contacts on printed wiring boards (PWBs) during a wave soldering operation. The shield is a trough shaped member that is attached by a frame assembly to a conveyor rail of a conventional wave soldering machine. The frame assembly includes a pair of support sleeves to which the two ends of the shield are attached. The support sleeves are movable with respect to the conveyor rail between a retracted position and any desired extended position by means of a motor, and a chain and sprocket drive mechanism. A motor control circuit enables the shield to be positioned as desired, and a position responsive sensor is attached to the drive mechanism to provide signals for a position indicating display. The motor control circuit can be either manually controlled, or automatically controlled by a microprocessor.

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 an apparatus for solder plating parallel arranged leads on an electronic device, e.g. QFP having leads on four sides or SOLC having leads on two sides. A metal plate of solder wettable material having an inclined upper surface is placed in a molten solder bath. The electronic device, with the leads to be solder plated exposed, is lowered horizontally in the solder bath and is pulled out horizontally. A large quantity of solder adhering on the inclined plate pulls solder adhering on the leads sequentially along an inclined surface of the plate to obtain uniform thickness of solder plating on the leads without causing bridging.

Abstract: The wave barrier device of the invention comprises a flap which is rigidly joined to the soldering machine. This flap plunges lightly into the molten tin bath and pushes it before the board which is precedes.

Abstract: A soldering mask for soldering the leads of leaded components to a circuit pattern on a surface of a circuit board also having surface mounted components already soldered to the circuit pattern on that surface, comprises a flat metal plate having a recess in the top surface of the plate for reception of the circuit board. Cavities in the bottom surface of the recess house the surface mounted components. Openings through the plate from the bottom surface of the recess permit passage of leads and also permit access by the solder to solder the leads to the circuit pattern.

Abstract: A set of titanium guide bars are shaped with inner angular finger shields to isolate designated underside edge areas of a printed circuit board being conveyed across a molten solder bath in a wave solder machine.

Abstract: A soldering mask for use with a wave soldering machine. The soldering mask is formed into a trough-like shape which is positioned in the machine to displace molten solder away from the part of the work which is not to be soldered. The mask is made of titanium and includes positioning members to accurately position the mask between the part to be free of solder and the wave of molten solder.

Abstract: An apparatus is disclosed for removing or installing at least one through-hole mounted component from a printed circuit board or the like, the apparatus including a compliant mask for contacting and supporting the printed circuit board with the mask having at least one hole extending therethrough and the hole being aligned with the component. A conduit is provided for directing liquid solder into the hole in the mask to contact leads of the component and thus facilitate installation or removal thereof from the board.

Abstract: An apparatus for automatically coating terminal leads of electrical components such as IC with solder for improving solderability thereof. A plurality of IC stored in a row within a container placed at a predetermined feed location are automatically fed onto a track extending adjacent to a series of work stations arranged in a straight path and including a soldering station in which IC are contacted with a solder wave. Driving means is provided for displacing along the track the row of IC fed thereon. The worked IC are automatically collected within an empty container placed at a predetermined receipt location.

Abstract: Pressurized molten solder 71 is flowed along a confined first channel 86 and forced through a series of spaced, aligned apertures 88 as solder jets which rise, fall and merge to form a solder stream which flows along a second channel defined by channel walls 93 and 94. Spring held printed circuit boards 10 are advanced by a conveyor 21 which is tilted to move a far section of each board into engagement with the top of channel wall 93 and then a near section of each board into engagement with the top of channel wall 94 whereafter the board is spring held to ride along the tops of channel walls while a thin stripe of solder is applied to the board.

Abstract: An apparatus for soldering the wires of the rotor winding of an electric machine to its commutator. The apparatus comprises a tank with molten solder and heaters, a magneto-hydrodynamic pump for the solder, a device for holding the rotor, and a device for the protection of the molten solder from oxidation. The device for holding the rotor comprises a base in the shape of a hollow cylinder with holes and having a chamfered bottom part of the internal surface thereof in which there is movable disposed a replacement nozzle, which is made up of a sleeve and a rotor holding case rigidly connecting together. The nozzle reciprocates in the base. The commutator of the rotor to be solder is inserted into the case. Between the sleeve and the case there is formed a ring-shaped duct, connected with a booster zone which directs the molten solder toward the commutator.

Abstract: An apparatus for desoldering and soldering multipin components to or from printed circuit boards is described. A shallow large area solder pot, surrounded by a recessed area to catch overflow, in combination with a flexible mask is used to apply molten solder to a selected area of a printed circuit board to desolder or solder a selected device.

Abstract: A solder mask (62) of special construction is mounted on each of a plurality of crystal filters (10) having continuous seams (16) defined by peripheral edges (20) of filter metal covers (14) and peripheral portions (18) of filter metal headers (12). The crystal filter-solder mask assemblies (10,62) then are passed over a solder wave (24) to solder the continuous seams (16) of the crystal filters (10) simultaneously. The crystal filters (10) are suspended on magnetic carriers (104) of an endless conveyor (106) as the filters pass over the solder wave. During the wave-soldering operation the solder masks (62) preclude solder from access to various critical areas of the crystal filters (10).

Abstract: Apparatus for soldering the winding of armatures of electrical machines to the collectors thereof. The apparatus includes a device for gripping, displacing and fixing the armature with the collector, a single-phase magnetic-hydrodynamic pump with metal conduit and a bath with molten solder and heaters. The magnetic core of the single-phase magnetic-hydrodynamic pump is embraced by a metal conduit disposed underneath the bottom of the bath, and the inlet of the metal conduit is connected to the bottom of the bath, while its outlet end is rigidly connected to a casing fastened to the bottom of the bath. To the bottom of the casing there is pressed by means of an easily releasable joint a changeable nozzle unit. When it is necessary to solder a collector with a diameter different from the previous one, the changeable nozzle unit is taken out of the apparatus and new one of a size corresponding to that of the collector to be soldered is inserted in the apparatus.

Abstract: Component masks are described for preserving unoccupied holes in a printed circuit board when such board is subjected to wave soldering. Each mask is a body of plastic resistant to adherence to the solder and capable of withstanding the temperature of solder when the printed circuit board is subjected to wave soldering and includes a supporting block from which a plurality of parallel pins protrude for reception into the printed circuit board lead-holes to be preserved. The pins are spaced from one another by distances equal to the distances between lead-holes on a printed circuit board, and component masks are provided respectively having a single row and a double row of such pins. Each pin is tapered slightly toward its free end, and is connected to its associated supporting block by a conically shaped transition body.

Abstract: A component protective system is disclosed for an electrical component which can be soldered in a printed circuit board by means of a solder bath. A portion of the components which projects through the printed board is protected from the influence of the solder bath by use of a protective collar arranged around the portion to be protected. The protective collar is open in a direction toward the solder bath and projects beyond the portion to be protected. Upon immersion of the component together with the printed circuit board into a solder bath, an air cushion is formed within the protective collar. This air cushion prevents contact between the solder and the portion to be protected and forms a heat insulator which protects this portion from heat damage.

Abstract: Apparatus for soldering the wires of the coil on the armature of an electric machine to the commutator thereof. The apparatus has a device for clamping, shifting and fixing the armature, a monophase magnet-hydrodynamic pump with a charger and a pan with molten solder. The magnetic core of the pump has the shape of a hollow cylinder and is externally chamfered at its upper end. The armature to be soldered is disposed vertically with the lower portion of its commutator telescoped within the upper end of the core. Around the core within the pan there is an annular charger disposed coaxially of the core, the charger having its lower end above the bottom of the pan and its upper end on the level of the upper chamfered end of the core so as to form between the upper end of the charger and the upper chamfered end of the core an annular frusto-conical channel with a discharge end directed toward the upper portion of the commutator and the parts of the wires adjacent thereto to solder the wires to the commutator.

Abstract: A device is described for masking the gold connector tabs located along the edges of printed circuit boards to prevent the connectors from becoming solder coated during wave solder operations. The device is comprised of a pair of angle sections coupled to each other by tensioning means. The sections are easily applied to the circuit board assembly without scratching the gold contacts. Moreover, they provide stiffness to the board and a dam to prevent solder from flowing over the board and damaging the electrical components mounted thereon during wave soldering. The device is easily removable from the circuit boards after soldering and is reusable. Finally, the device of the present invention is characterized by long life, reasonable cost and ease of use.