Abstract: A lead free solder hierarchy for use in the second level solder connection of electronic components such as joining an electronic module to a circuit board. An off-eutectic solder concentration of SnCu or SnAg is used for the module side connection. This off-eutectic solder contains sufficient intermetallics to provide the module side connection with a robust second level assembly and rework process. The off-eutectic composition provides an inter-metallic phase structure in the module side fillet during assembly. The inter-metallic phase structure eliminates problems of tilt and collapse during second level assembly and aids in rework by providing a more cohesive joint allowing removal of the columns from the board without simultaneous removal from the module.

Abstract: Methods and apparatus for forming a plurality of uniformly sized solder balls utilize a stencil having a plurality of holes of uniform volume disposed on a substrate. Solder is disposed in the holes of the stencil on the substrate. Typically, the solder is in the form of solder paste which is distributed into the holes using a squeegee. While within the holes of the stencil on the substrate, the solder is melted to form solder balls. The stencil may then be removed to leave the solder balls on the substrate, or the solder balls may be removed while the stencil remains on the substrate.

Abstract: In a solder that realizes high-temperature-side solder bonding in temperature-hierarchical bonding, a connection portion between a semiconductor device and a substrate is formed of metal balls made of Cu or the like and compounds formed of metal balls and Sn, and the metal balls are bonded together by the compounds.

Abstract: A method for fabricating a reactive solder or braze includes forming a metallic matrix with an interior region and surface regions by actively providing a higher concentration of reactive atoms to the interior region than to the surface regions.

Abstract: Improved fluxless soldering processes are disclosed. In accordance with one technique, a solder preform having a plurality of voids formed on its primary surfaces is disposed between metallized surfaces of a pair of members to be joined. Upon reaching the reflow temperature, fresh solder flows into the voids and wets portions of the metallized surfaces, thus overcoming the solder surface oxidation problem common to fluxless soldering processes. In accordance with another technique, a solder preform having primary surfaces coated with a thin layer of a noble metal is employed. The noble metal substantially prevents oxidation of the solder performs surfaces while the preform is heated to reach reflow temperature. As the solder temperature increases, portions of the noble metal are dissolved into the bulk solder material. Thus, during reflow, non-oxidized bulk solder material is enabled to wet the metallized surfaces of the pair of members.

Abstract: An article includes turbulation material bonded to a surface of a substrate via a bonding agent, such as a braze alloy. In an embodiment, the turbulation material includes a particulate phase of discrete metal alloy particles having an average particle size within a range of about 125 microns to about 4000 microns. Other embodiments include methods for applying turbulation and articles for forming turbulation.

Abstract: A braze preform and a method for making the braze preform are disclosed. The braze preform includes a filler metal that has been sintered to produce a liquid phase of at least a portion of the filler metal.

Abstract: A process of making a multi-layer thermal interface material is depicted. The multi-layer thermal interface material is attached between an integrated heat spreader and a die. Processing of the multi-layer thermal interface material includes stamping or other pressure processing.

Abstract: This invention relates to a composition for repairing metallic articles which in its initial state is in the form of an adhesive, self-supporting putty, capable of being molded including 5-15% by weight of a sacrificial binder containing at least one acrylic resin and volatile solvent. The invention also relates to a kit for the composition and methods for repair.

Abstract: Lead-free solder alloys based on a Sn—Ag—Mg system are disclosed. The alloy compositions have a melting temperature close to 183° C. and a similar surface tension to that of Sn—Pb solder, and can thus be a readily substituted for conventional Sn—Pb solders. P may be added to the alloy compositions to reduce its tendency of oxidation.

Abstract: A solder preform having multiple layers including a solder layer filled with additives interposed between two unfilled layers for improved wettability. A solder preform having a sphere which contains a solder material filled with additives, and an unfilled surface layer for improved wettability. A thermal interface material having a bonding component and an additive component which is a CTE modifying component and/or a thermal conductivity enhancement component. Active solders containing intrinsic oxygen getters.

Abstract: Minute copper balls having a high sphericity which are suitable for use as the cores of copper core solder balls are manufactured by heating small pieces comprising an alloy of 0.5-40 wt % of Zn and a remainder of Cu to at least the melting point of Cu without the pieces contacting each other to give them a spherical shape and cooling the resulting spheres to form solid balls. The minute copper balls which are obtained comprises 0.01-0.5 wt % of Zn and a remainder of Cu and have a spherical shape with a diameter in the range of 50-1000 &mgr;m.

Abstract: Improved fluxless soldering processes are disclosed. In accordance with one technique, a solder preform having a plurality of voids formed on its primary surfaces is disposed between metallized surfaces of a pair of members to be joined. Upon reaching the reflow temperature, fresh solder flows into the voids and wets portions of the metallized surfaces, thus overcoming the solder surface oxidation problem common to fluxless soldering processes. In accordance with another technique, a solder preform having primary surfaces coated with a thin layer of a noble metal is employed. The noble metal substantially prevents oxidation of the solder performs surfaces while the preform is heated to reach reflow temperature. As the solder temperature increases, portions of the noble metal are dissolved into the bulk solder material. Thus, during reflow, non-oxidized bulk solder material is enabled to wet the metallized surfaces of the pair of members.

Abstract: A solder ball achieves a desired quantity of solder material for a solder joint easily without increasing the thickness of a solder layer formed to cover a core. The solder ball comprises a conductive core having depressions on its outer surface, and a solder layer formed to cover the outer surface of the core in such a way as to fill the depressions of the core. Thus, the quantity of the solder material included in the ball is supplemented by the solder material filled into the depressions. Preferably, the core has a higher melting point than the solder layer and wettability to the solder layer. The core may have a cavity in its inside, thereby forming a shell-shaped core. The core may be made of a porous metal body having pores, in which part of the pores reaches the outer surface of the core, thereby forming the depressions.

Abstract: In a method of soldering the surfaces of a component (11) to a substrate (12), a solder preform (15) is located in the gap between the surfaces. The solder is heated and an over pressure applied to move the surfaces together whilst the solder is molten. Abutments (17) between the surfaces limit the spacing between them. A trapped void (18) is decreased in volume as the pressure is applied. The method is particularly applicable to monolithic microwave integrated circuits (MMIC) and reduces void areas in joints.

Abstract: A solder metal made of a eutectic or stoichiometric composition including at least two metallic or semiconducting elements is applied to a contact (of the semiconductor component, brought into contact with the metal layer of a metallized film and alloyed by heating into the metal layer of the film, thereby producing an electrically conductive connection having a higher melting point. A solder metal that is particularly suitable for such a purpose is the Bi22In78 (melting point 73° C.), Bi43Sn57, or In52Sn48, or BiIn, or BiIn2.

Abstract: A method for producing titanium alloy brazing strips and the resulting brazing strips and/or foils. The method uses a cold-rolling process without heat treating to generate a titanium based multi-layer alloy strip or foil made up of discrete layers of titanium and an additional layer or layers of one or more metals, such as zirconium, nickel and/or copper, for example, or alloys thereof, with the layer of titanium roll bonded without heat treating to the layers of the additional metal(s). The resulting strip or foil can include, for example, Cu/Ti/Cu, Ni/Ti/Ni, Ni/Ti/Cu, Cu/Ni/Ti/Ni/Cu, Ni/Cu/Ti/Cu/Ni, Ni/Cu/Ni/Ti/Ni/Cu/Ni, Ni/Zr/Cu/Ti/Cu/Zr/Ni and Ni/Ti/Cu/Zr/Cu/Ti/Ni among other combinations. The resulting strip or foil can be used for brazing, creating an alloy of the weight percentage of the original materials.

Abstract: A solder ball holding terminal has a first plate, a second plate and a third plate integrally formed with and sandwiched between the first plate and the second plate. The first plate has a first distal end, the second plate has a second distal end and the third plate has a third distal end and a fourth distal end. A distance between the third distal end and the fourth distal end is much smaller than that between the first distal end and the second distal end such that when a solder ball is inserted into a space defined among the first distal end, the second distal end, the third distal end and the fourth distal end, a substantially three-point support is provided to the solder ball so that the solder ball is securely clamped.

Abstract: Methods and apparatus for forming a plurality of uniformly sized solder balls utilize a stencil having a plurality of holes of uniform volume disposed on a substrate. Solder is disposed in the holes of the stencil on the substrate. Typically, the solder is in the form of solder paste which is distributed into the holes using a squeegee. While within the holes of the stencil on the substrate, the solder is melted to form solder balls. The stencil may then be removed to leave the solder balls on the substrate, or the solder balls may be removed while the stencil remains on the substrate.

Abstract: A method of joining surfaces comprising: providing a first surface comprising a layer of silver; interposing between the first surface and a second surface a eutectic composite which melts below 140° C.; raising the temperature of the eutectic composite to a first temperature above the eutectic temperature to at least partially melt the eutectic composite and form molten eutectic alloy; and contacting the molten eutectic alloy with silver layer of the first surface so as to cause inter-diffusion and reaction between the eutectic alloy and the silver, wherein the relative proportions of silver and eutectic composite are selected such that a non-eutectic composition forms between silver and the metals contained in the eutectic composite, the non-eutectic composition having a melting temperature higher than said first temperature.

Abstract: A weld wire for storage on a spool of weld wire. The weld wire has a substantially linear cast in the form of an undulating curve that generally lies in a single plane. The undulating curve is a succession of generally semi-circular sections having a generally fixed radius of curvature. The linear cast is formed on the weld wire prior to the weld wire being wound on the spool of weld wire. The linear cast is at least partially retained on the weld wire after the weld wire is unwound from the spool and during the feeding of the weld wire through a welding machine.

Abstract: A lead free solder hierarchy for use in the second level solder connection of electronic components such as joining an electronic module to a circuit board. An off-eutectic solder concentration of SnCu or SnAg is used for the module side connection. This off-eutectic solder contains sufficient intermetallics to provide the module side connection with a robust second level assembly and rework process. The off-eutectic composition provides an inter-metallic phase structure in the module side fillet during assembly. The inter-metallic phase structure eliminates problems of tilt and collapse during second level assembly and aids in rework by providing a more cohesive joint allowing removal of the columns from the board without simultaneous removal from the module.

Abstract: A tin-lead solder alloy containing copper and optionally silver as its alloying constituents. The solder alloy consists essentially of, by weight, about 55% to about 75% tin, about 11% to about 44% lead, up to about 4% silver, nickel, palladium, platinum and/or gold, greater than 1% to about 10% copper, and incidental impurities. The solder alloys contain a small portion of CuSn intermetallic compounds, and exhibit a melting mechanism in which all but the intermetallic compounds melt within a narrow temperature range, though the actual liquidus temperature of the alloys may be considerably higher, such that the alloys can be treated as requiring peak reflow temperatures of about 250° C. or less. The intermetallic compounds precipitate out to form a diffusion barrier that increases the reliability of solder connections formed therewith.

Abstract: A method of manufacturing an article of manufacture for use in a fluxless brazing process is disclosed. The method comprises the step of applying a braze-promoting layer including one or more metals selected from the group consisting of nickel, cobalt and iron, onto a bonding layer which comprises one or more metals selected from the group consisting of zinc, tin, lead, bismuth, nickel, antimony and thallium and which is disposed on a substrate including aluminum.

Abstract: A method of manufacturing an article of manufacture for use in a fluxless brazing process is disclosed. The method comprises the step of applying a braze-promoting layer including one or more metals selected from the group consisting of nickel, cobalt and iron, onto a bonding layer which comprises one or more metals selected from the group consisting of zinc, tin, lead, bismuth, nickel, antimony and thallium and which is disposed on a substrate including aluminum.

Abstract: An apparatus and method for welding members that are formed at least in part of aluminum. A welding assembly is constructed and arranged to position a welding material in electrically conductive relation between exterior surface portions of first and second weldable members at a location where the first and second weldable members are to be joined. The welding material assembly includes at least one welding material member mounted on a flexible carrier sheet in a predetermined arrangement with each welding material member being constructed of an electrically conductive metallic welding material capable of melting when heated by application of an electrical current. A welding method includes alternatively attaching the welding material members to a weldable member without a carrier sheet, by a welding process.

Abstract: A weld wire for storage on a spool of weld wire. The weld wire has a substantially linear cast in the form of an undulating curve that generally lies in a single plane. The undulating curve is a succession of generally semi-circular sections having a generally fixed radius of curvature. The linear cast is formed on the weld wire prior to the weld wire being wound on the spool of weld wire. The linear cast is at least partially retained on the weld wire after the weld wire is unwound from the spool and during the feeding of the weld wire through a welding machine.

Abstract: A method of constructing a preform for use in forming a machined structural assembly is provided. The method includes determining the dimensions of the machined structural assembly. First and second structural members are selected based on the predetermined dimensions of the machined structural assembly. The first structural member is positioned adjacent the second structural member so as to define at least two contact surfaces. The contact surfaces of the first and second structural members are friction welded to construct the preform such that the preform has dimensions approximating the dimensions of the machined structural assembly to thereby reduce material waste when forming the machined structural assembly. A machined structural assembly having predetermined dimensions is formed from the preform by machining away excess material.

Abstract: The apparatus for operating on a workpiece includes a die defining first and second apertures and an interior therebetween. The first aperture and the interior of the die are structured to receive the workpiece. The interior of the die can be structured to shape the workpiece into a predetermined configuration. The apparatus includes at least one rotatable pin extending at least partially into the interior of the die. The pin is structured to at least partially stir the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece.

Abstract: A ribbon of colour A metal is combined with a thin layer of soldering alloy, bent and soldered to form a tube, it is then filled with a core of colour B metal. The compound is then drawn and/or laminated until it is transformed into a long ribbon or into a wire, externally of colour A and internally of colour B. The filled ribbon or wire is wrapped like a solenoid around a deformable support, like a metal mesh and stamped into the desired shape. The resulting two faced element is then ground in order to remove, all along a strip and following a line or in dots, the superficial part of colour A until the core of colour B is revealed. The bi-coloured long element is then treated like a single body and allows the realisation of precious bi-coloured ornamental items.

Abstract: A lead-free solder includes at least one selected from 0.01 to 1% by weight of Co, 0.01 to 0.2% by weight of, Fe, 0.01 to 0.2% by weight of Mn, 0.01 to 0.2% by weight of Cr, and 0.01 to 2% by weight of Pd; 0.5 to 2% by weight of Cu; and 90.5% by weight or more of Sn. This solder exhibits a satisfactory solderability in solder joints and shows a high resistance to electrode leaching upon soldering or when the resulting soldered article is left at high temperatures.

Abstract: A family of low temperature brazing alloys wherein the alloy is utilized in the form of a filler metal or shim and consists of electroplated nickel on zinc shimstock, wherein the zinc shimstock includes zinc, aluminum and silicon, with or without a small amount of lead, tantalum or bismuth. The use of the brazing alloys for the joining aluminum parts together or an aluminum part to a part of another metal, such as brass. Further, metallic coating could be thermally spray coated and powder metals could be utilized as the filler materials with equally acceptable brazing techniques. Using these techniques, the brazing could be accomplished at a temperature in the range of 750 to 1050° F.

Abstract: Lead-free solder alloys based on a Sn—Ag—Mg system are disclosed. The alloy compositions have a melting temperature close to 183° C. and a similar surface tension to that of Sn—Pb solder, and can thus be a readily substituted for conventional Sn—Pb solders. P may be added to the alloy compositions to reduce its tendency of oxidation.

Abstract: Lead-free solder alloys based on a Sn—Zn—Mg system are disclosed. The alloy compositions have a melting temperature close to 183° C. and a similar surface tension to that of Sn—Pb solder, and can thus be a readily substituted for conventional Sn—Pb solders. P may be added to the alloy compositions to reduce its tendency of oxidation.

Abstract: A two-part solder preform for use in attaching a leaded circuit component to a circuit board. The preform is formed by two different solid components, a first of which is formed of a lower-temperature solder alloy and the second of a higher-temperature solder alloy, in which the first solid component is present in a sufficient amount to dissolve the second solid component when the preform is heated above the melting temperature of the lower-temperature solder alloy but below the melting temperature of the higher-temperature solder alloy. Upon cooling, the preform yields a solder joint having a substantially homogenous composition, which bonds the lead to the circuit board. Preferred solder alloys for the first and second solid components are lead-free.

Abstract: The invention provides metal connecting composition for connecting metal to metal with removing oxide film on the mother metal surface. The metal connecting composition contains metal particles and hydrocarbon compound having C—H bonding dissociation energy of a value equal to or lower than 950 KJ/mol. When metal pieces between which the metal connecting composition is applied is heated, the hydrocarbon compound is dehydrogenated to form radical, and the radical reduces oxide film on the metal surface to be connected.

Abstract: Minute copper balls having a high sphericity which are suitable for use as the cores of copper core solder balls are manufactured by heating small pieces comprising an alloy of 0.5-40 wt % of Zn and a remainder of Cu to at least the melting point of Cu without the pieces contacting each other to give them a spherical shape and cooling the resulting spheres to form solid balls. The minute copper balls which are obtained comprises 0.01-0.5 wt % of Zn and a remainder of Cu and have a spherical shape with a diameter in the range of 50-1000 &mgr;m.

Abstract: A method for fabricating cylindrical sputter targets for rotary cylindrical cathodes used in depositing a dielectric layer of desired alloy on non-planar substrates during sputtering is disclosed. The method includes forming a cooling tube having a passage within to receive a cooling medium, then fabricating multiple annular rings including each of the basic metal constituents of the desired alloy and attaching the annular rings to the cooling tube such that the exposed outer portions of the annular rings provide a homogeneous layer of the desired alloy on the non-planar substrates during sputtering.

Abstract: It is an object of the present invention to provide spherical metal particles having excellent monodispersity. The present invention relates to a method of manufacturing monodisperse spherical metal particles characterized by passing liquid metal through a porous membrane so as to disperse the resulting liquid metal particles in a continuous liquid phase.

Abstract: A braze preform and a method for making the braze preform are disclosed. The braze preform includes a filler metal that has been sintered to produce a liquid phase of at least a portion of the filler metal.

Abstract: A soldering gun, a solder pellet having a predetermined amount of solder, solder pellet dispensing wheel, kit related thereto and method of soldering is provided herein. The present invention provides a device for dispensing solder that includes a dispensing wheel that has a plurality of radially disposed dispensing wheel solder pellet retaining compartments. The compartments are sized to accommodate a predetermined size, single application solder pellet. The kit for dispensing solder comprises at least two of a fine solder pellet dispensing wheel having a plurality of fine solder pellets, a medium solder pellet dispensing wheel having a plurality of medium solder pellets, or a thick solder pellet dispensing wheel having a plurality of thick solder pellets. The kit also includes a portable, hand held, soldering device mating with the solder dispensing wheel.

Abstract: A process for producing a solder sheet with a bump grid array includes the step of molding a sheet of solder material in a mold having two mold halves. Each of the mold halves is formed with an array of first recesses. At least one of the mold halves is further formed with a plurality of second recesses interconnecting adjacent pairs of the first recesses. Each of the first recesses has a depth deeper than that of the second recesses. The first recesses of one of the mold halves are registered with the first recesses of the other of the mold halves such that the first and second recesses of the mold halves cooperatively form a mold cavity defining the shape of the molded solder sheet when the mold halves are brought toward each other to close the mold.

Abstract: A weld wire for storage on a spool of weld wire. The weld wire has a substantially linear cast in the form of an undulating curve that generally lies in a single plane. The undulating curve is a succession of generally semi-circular sections having a generally fixed radius of curvature. The linear cast is formed on the weld wire prior to the weld wire being wound on the spool of weld wire. The linear cast is at least partially retained on the weld wire after the weld wire is unwound from the spool and during the feeding of the weld wire through a welding machine.

Abstract: Disclosed is a solder alloy in use for bonding electric or electronic parts, containing: 3 to 12% by weight of a zin component; and a tin component. The oxygen content of the solder alloy is reduced to 100 ppm or less. Using the solder alloy, a bonding portion is formed on the substrate and the electronic part is mounted thereon to obtain a substrate for mounting the electronic part and a substrate on which the electronic part is mounted. The bonding portion made of the above solder alloy can prevent migration.

Abstract: An apparatus for placing an array of solder balls on a substrate includes a carrier plate having an array of holes therethrough. Each hole is capable of holding a solder ball. A ball placement head having an array of pins is aligned with a desired pattern of solder balls held by the carrier plate. The array of pins push the pattern of solder balls through the holes in the carrier plate onto the substrate.

Abstract: Process for producing electrical connections on the surface of a semiconductor package containing an integrated-circuit chip and having metal electrical-connection regions on the surface of the package, consisting of: covering these connection regions with a first metal layer forming an anti-diffusion barrier; covering this first layer with an anti-oxidation second metal layer; and depositing a metal solder drop or solder ball on the second metal layer. The solder drop comprises an addition of metal particles in suspension which contain at least one of the metals of the first metal layer so as to produce a precipitate comprising these additional metal particles and at least partly the metal of the second metal layer, the precipitate remaining in suspension in the solder drop.

Abstract: Disclosed is a solder material and a manufacturing method thereof. The solder material has a first layer composed of a first metallic material and a second layer composed of a second metallic material which is different from the first metallic material, the first layer being formed in an elongated shape having axiality, and the second layer covering the first layer to surround the axis of the first layer. The solder material is in a form of a wire, a granule, a sheet, a tape or a planar fragment. The manufacturing method includes: covering a first metallic material with a second metallic material which is different from the first metallic material to prepare a covered body; and rolling the covered body to prepare a solder material comprising a first layer formed of the first metallic material in an elongated shape having axiality and a second layer covering the first layer to surround an axis of the first layer.

Abstract: A Pb-free solder alloy and a soldered bond using the same, in which the solder alloy has no harmful environmental effect but has a solderability comparable to that of the conventional Pb—Sn solder alloy. The solder alloy of the present invention either consists of Zn: 3.0-14.0 wt %, Al: 0.0020-0.0080 wt %, and the balance of Sn and unavoidable impurities or consists of Zn: 3.0-14.0 wt %, Bi: 3.0-6.0 wt %, Al: 0.0020-0.0100 wt %, and the balance of Sn and unavoidable impurities. The soldered bond of the present invention consists of either of the present inventive solder alloys.

Abstract: A method of attaching a lid with at least a metallic surface thereon to a substrate to enclose a surface acoustic wave electronic circuit using a fluxless solder preform having an undesired oxide surface and associated with the metallic surface on the lid and in superimposed and abutting relationship with a gold seal ring surrounding the electronic circuit to form a unit that is heated in a furnace having a hydrogen atmosphere such that the hydrogen removes any undesired oxide surfaces from the solder preform and the metallic surface on the lid by combining with the oxygen therein to form moisture so as to remove any oxide surfaces from the solder preform and the lid metallic surface and enable a complete bonding of the fluxless solder preform with the gold seal ring and the lid metallic surface thereby forming a hermetically sealed package.

Abstract: A method for joining a multiplicity of multi-alloy solder columns to an electronic substrate and the structure formed by such method are disclosed. In the method, a mold plate equipped with a multiplicity of cavities is first filled by an injection molded solder technique with a high temperature solder forming a multiplicity of solder columns. The mold plate is then sandwiched between an extraction plate and a transfer plate by utilizing a multiplicity of displacement means equipped in the extraction plate to displace the multiplicity of solder columns from the mold plate into a multiplicity of apertures equipped in the transfer plate. The multiplicity of cavities in the transfer plate each has a straight opening and a flared opening. The flared opening is then filled with a low temperature solder paste to encapsulate one end of the high temperature solder column.