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: The present invention is directed to a solder flux and solder paste that comprises methylsuccinic acid as an activating component and an imidazole compound as an accelerating component. The imidizole compound is selected from the following: 2-methyl-4-ethylimidazole, 2-methylimidazole and 2-ethylimidazole and mixtures thereof. The present invention is also directed to a method for preparing the above-described solder flux and method for soldering using the solder flux paste. It is also directed to an electronic component assembly joined using the solder flux paste.

Abstract: A thermal interface material for use in electronic packaging, the thermal interface material comprises a solder with relatively high heat flow characteristics and a CTE modifying component to reduce or prevent damage due to thermal cycling. The thermal interface material comprises an active solder that contains indium and an intrinsic oxygen getter selected from the group consisting of alkali metals, alkaline-earth metals, refractory metals, rare earth metals and zinc and mixtures and alloys thereof. Lastly, damage due to an electronic package due to thermal cycling stress is reduced by using an insert in a lid of an electronic device package wherein the insert has a coefficient of thermal expansion that is between about that of the lid and about that of a semiconductor substrate.

Abstract: A mist of liquid coolant is introduced into the path of atomized, molten, solder droplets. The mist and other conditions within the chamber are engineered to enable the liquid coolant droplets in the mist to contact the surfaces of molten solder droplets and be flash vaporized upon contact, thereby rapidly extracting heat from the molten solder droplets and accelerating cooling and solidification to produce an enhanced solder ball as a product of this process.

Abstract: A soldering flux includes a resin in an aqueous composition. The flux can also include an activating agent and a surface-active agent that promotes surface wetting. The flux can be used to coat circuits and a printed circuit board. The resin can be non-acidic and/or in an emulsified form.

Abstract: A soldering flux includes a solvent, an activator in the solvent, and cationic and nonionic surfactants. The soldering flux can be applied to a substrate, such as a printed circuit board before solder is applied.

Abstract: A method of efficiently coating surfaces of solder alloy spheres by a vapor deposition process using a solvent-based coating solution including a low viscosity organic material and at least one solute, such as a surfactant. The method surface coats solder alloy spheres to minimize or eliminate physical and chemical damage to surfaces of spheres prior to use in surface mounting applications.

Abstract: A thermal interface material for use in electronic packaging, the thermal interface material comprises a solder with relatively high heat flow characteristics and a CTE modifying component to reduce or prevent damage due to thermal cycling. The thermal interface material comprises an active solder that contains indium and an intrinsic oxygen getter selected from the group consisting of alkali metals, alkaline-earth metals, refractory metals, rare earth metals and zinc and mixtures and alloys thereof. Lastly, damage due to an electronic package due to thermal cycling stress is reduced by using an insert in a lid of an electronic device package wherein the insert has a coefficient of thermal expansion that is between about that of the lid and about that of a semiconductor substrate.

Abstract: A container device with an adjustable volume is provided for holding and immobilizing solder spheres used in manufacturing printed circuit boards and other electronic assemblies. The container device includes a hollow containing portion having a first terminal end and a second terminal end with a side wall connecting the first and second terminal ends and a removable sealing mechanism connected to the first terminal end. An adjustable piston is positioned within the containing portion having a length and a width such that when the piston is inserted into the containing portion of the container device, the piston exerts a sufficient pressure against the side wall of the containing portion to rigidly position the piston within the container device. The pressure exerted by the piston forms a seal between the piston and the side wall of the containing portion, thereby preventing solder spheres contained therein from slipping between the piston and the side wall.

Abstract: A containing device and method to hold and immobilize solder spheres during storage and transport including a container portion having an open top terminal end and an opposing closed bottom terminal end with at least one side wall connecting each terminal end, a removably attachable lid to seal the container portion and a lid insert for insertion into the container portion to immobilize solder spheres contained therein. In one embodiment, the lid insert is comprised of compressible material, such as a polymeric foam, whereby insertion of the lid insert into the container portion causes compression of the lid insert substantially adjacent to the side wall of the container portion, a bottom planar surface of the lid and an uppermost surface layer of solder spheres to completely fill any open or dead space within the containing device. The lid insert forms a mechanical seal which immobilizes the solder spheres until the lid insert is removed from the containing device.

Abstract: Copper-containing surfaces, such as a copper surface for use in an electrical circuit, are protected by the provision of a bismuth metal coating immersion-plated from a moderately to strongly acidic plating bath. The plating bath preferably contains dissolved bismuth, halide, and a sulfur-containing ligand as a complexing agent that promotes adhesion of the bismuth coating. The bath may be formed from a concentrate system combined with water. The concentrate system may be a two-component system having an acidic first component containing the bismuth, halide, and sulfur-containing ligand, and an alkaline second component containing an additional complexing agent (e.g., EDTA salt). Tarnish resistance of the plated bismuth can be improved by the application of an alkaline composition to neutralize residual acid. Plating thickness can be enhanced by pre-cleaning the surface to be plated with a pre-cleaner containing nitric acid.

Abstract: A flip chip having solder bumps, an integrated underfill, and a separate flux coating, as well as methods for making such a device, is described. The resulting device is well suited for a simple one-step application to a printed circuit board, thereby simplifying flip chip manufacturing processes which heretofore have required a separate underfilling step.

Abstract: A flip chip having solder bumps, an integrated underfill, and a separate flux coating, as well as methods for making such a device, is described. The device is characterized in that the underfill material is provided on the chip surface prior to the application of solder bumps, and then treated to form apertures therein which act as a mask for solder bump application. The resulting device is well suited for a simple one-step application to a printed circuit board, thereby simplifying flip chip manufacturing processes which heretofore have required a separate underfilling step.

Abstract: The present invention relates to a process for forming a two-stage bump on a flip chip. The process employs an underfill material which can be formed to act as a mask for application of bumps formed from a first composition to the flip chip. A material having a different composition can then be applied to the bumps.

Abstract: A sealing glass paste which comprises at least one sealing glass frit powder and an aqueous binder which comprises an aqueous solution, dispersion or emulsion of a polymeric material and a water soluble oxidant which decomposes at a temperature of below 475° C., the polymeric material burning out or decomposing at a temperature of below 475° C., in the presence of the oxidant, to leave less than 2% of residues based on the total weight of the solids content of the binder. The sealing glass pastes may be used in the assembly of cathode ray tubes. The aqueous binder system which is used results in low carbonaceous residue levels after firing and does not contain volatile organic solvents. Furthermore, using this aqueous binder system sealing glass pastes can be prepared with sealing glasses which include PbO therein.

Abstract: Copper-containing surfaces, such as a copper surface for use in an electrical circuit, are protected by the provision of a bismuth coating.

Abstract: A resin-based VOC-free soldering flux consists of 40 to 50 wt % of a liquid epoxy resin, 25 to 30 wt % of a non-volatile liquid epoxy diluent, 20 to 33 wt % of a polyfunctional carboxylic acid, and 2.0 to 3.5 wt % of a thixotropic agent. There are no volatile organic solvents or compounds in the flux which can evaporate during the reflow process. The carboxylic acids are provided in powdered form and are suspended in the epoxy blend wherein they remain as solid particles until heated in the solder reflow process. A VOC-free solder paste formed from the flux consists of 40 to 95 wt % soldering particles, and 5 to 60 wt % of the VOC-free soldering flux. The thixotropic agent improves printability of the solder paste onto printed wiring boards. A VOC-free flux-core solder wire includes the VOC-free flux as the inner core of the wire with an outer shell of solder alloy.

Abstract: A process for the preparation of an anisotropic conducting material including the steps of providing a strip or sheet of a non-conducting matrix and laminating at least one layer of a release material to each side thereof to form a composite matrix, forming an array of holes in a predetermined pattern in the composite matrix, passing the matrix through a coating head which simultaneously fills the holes in the array in the composite matrix from both sides of the matrix with a conducting material, curing or drying the composite filled matrix and removing at least one layer of release material from each side of the matrix.

Abstract: The invention provides a solder preform coated with a predetermined thickness of parylene which physically and chemically protects the preform, as well as a provides a unique optical interference coating which reflects at characteristic frequencies. When predetermined thicknesses of parylene are selected, the parylene coating provides an interference coating which causes the solder preforms to appear green, or gold, or blue in color. The parylene coating, which is otherwise colorless and transparent thus enables solder preforms to be visually distinguishable by alloy type (or customer) by the use of colors, or blends of colors. The invention further provides an effective method of visually verifying the reflow status of a solder preform during manufacturing by examining the color of the solder preform after heating.

Abstract: Ordered Z-axis electroconductive sheet materials are produced by entrapping bodies of fusible, polymeric, electroconductive adhesive at predetermined spaced locations in a sheet-like carrier of fusible, polymeric, dielectric adhesive including a thermoplastic component. The materials are useful for mechanically joining and electrically connecting electronic circuit components.