International Business Machines Corporation

Lockheed Martin Corporation

James K Lake

Randy C Long

Stephen G Gonya

Roger N Wild

Paul T Coyne

Michael T Mallery

Tom Rovere

Peter Michael Ziolkowski

Rick Micha

Stephen E Boll

An assembly and method for mounting an electronic package to a printed circuit board (PCB) in which a gasket is shaped to fit tightly around and under a perimeter edge of an electronic package. The electronic package may be carried by the PCB and comprise electrical package contacts on an underside of the package, which contact PCB contacts on the PCB. The gasket may be disposed between the underside of the package and the PCB substrate and surround the contacts, and may be shaped to fit around and under a perimeter edge of the package to protect the contacts from contamination.

Electronic package mounting

Solder is deposited on chip elements or other potentially irregular surfaces by applying solder paste to a thin porous sheet such as cotton twill cloth so that the solder paste fills open areas therein. The solder volume is thus regulated by the texture and structure of the porous sheet. The porous sheet is then placed in compression against the surface to which solder is to be applied and the solder in the solder paste reflowed in an oven, preferably including a nitrogen atmosphere. At the same time, excess flux is absorbed by the porous sheet to facilitate subsequent cleaning while the reflow of solder is accurately and repeatably controlled. The process and resulting structure are particularly appropriate to the manufacture of discrete electronic devices which include an array of chip components such as capacitor chips sandwiched between plate structures. The process and structure also provides highly repeatable, high quality solder connections between curved surfaces.

Thin film solder paste deposition method and tools

A soldering iron tip includes a removable Invar shield covering a copper core plated with other metals. In one embodiment, the core is plated with iron and, outside a working section of the tip, with nickel and chrome. In another embodiment, the core is plated with chrome.

Soldering iron tip

Disclosed is a high solidus temperature, high service temperature, high strength ternary solder alloy. The components of the alloy are a major portion of Sn and lesser portions of Bi, and In.

Lead-free, high tin, ternary solder alloy of tin, bismuth, and indium

A high solidus temperature, high service temperature, high strength multi-component solder alloy having a major portion of Sn and effective amounts of Sb, Bi and Cu.

Lead-free, tin, antimony, bismtuh, copper solder alloy

Disclosed is a lead-free, high solidus temperature, high Sn alloy. The solder alloys contain in excess of 90 weight percent Sn, and an effective amount of Ag and Bi, optionally with Sb or with Sb and Cu. Another form of the alloy contains Ag and Sb, optionally with Bi.

High temperature, lead-free, tin based solder composition

The lead free alloy is a low solidus temperature, multi-component solder alloy containing at least about 50 weight percent Bi, up to about 50 weight percent Sn (basis total Sn and Bi), and an effective amount of a physical and mechanical property enhancing third component. The third component can be Cu, In, Ag, and combinations of Cu and Ag.

Lead free, tin-bismuth solder alloys

Disclosed is a high solidus temperature, high service temperature, high strength multi-component solder alloy containing a major portion of Sn, and effective amounts of Ag, Bi and In. Preferably the solder alloy contains 78.4 weight percent Sn, 2.0 weight % Ag, 9.8 weight % Bi, and 9.8 weight % In.

Growing community of inventors

Endicott, NY, United States of America

James K Lake