Solder paste

Abstract: A socket for attaching a flip chip die or ball grid array devices to a printed circuit board substrate having a pattern of solder covered lands, with resources for removing the flip chip die or ball grid array device, resources for directly aligning the solder balls of the flip chip die or ball grid array device to the printed circuit board, resources for using an interposer of dendrite coated vias or pads to electrically and physically connect the solder balls of the flip chip die or ball grid array devices to the solder deposits of the printed circuit board, resources for having the interposer reconfigure the wiring for testing or replacement purposes, resources for utilizing the flexibility and resilience of the interposer to improve dendrite connections, and resources for heat sinking the flip chip die or ball grid array device by direct thermal contact. The socket applies an evenly distributed force to connect the aligned flip chip die or ball grid array device solder ball pattern to the underlying printed circuit board solder deposit pattern through dendrite penetration of the solder using an interposer situated between and aligned to each such solder pattern.

Abstract: An improved solder interconnection for forming I/O connections between an integrated semiconductor device and a support substrate having a plurality of solder connections arranged in an area array joining a set of I/O's on a flat surface of the semiconductor device to a corresponding set of solder wettable pads on a substrate, the improvement being a band of dielectric organic material disposed between and bonded to the device and substrate embedding at least an outer row of solder connections leaving the center inner solder connections and the adjacent top and bottom surfaces free of dielectric material.

Abstract: A method of bonding a flexible circuitized substrate to a circuitized substrate (e.g., printed circuit board) to interconnect selected circuitry of both substrates using solder. Solder paste is applied over conductive pads on the circuitized substrate and organic dewetting material (e.g., epoxy coating) adjacent thereto. The flexible substrate, having conductors located within and/or traversing an aperture in the flexible substrate's dielectric, is positioned above the solder paste and heat is applied (e.g., in an oven). The paste, dewetting from the organic material, "balls up" and substantially surrounds a solder member (ball) attached to a bridging portion of the flexible substrate's conductor, thereby connecting both substrates. A frame member may be used to align the flexible substrate, both during solder member attachment thereto, as well as for aligning the flexible substrate having solder members attached, to the respective solder paste locations on the lower substrate.

Abstract: Conductive copper areas of printed circuits, such as through-holes, pads and lands, to which electronic components can thereafter be electrically connected by, e.g., wave soldering, are provided with a coating of nickel or cobalt, such as by electroless deposition from nickel-or cobalt-boron and nickel-or cobalt-phosphorous plating baths, or entirely or partly electrolytically, followed by a coating of a protective material which protects the nickel or cobalt coating from oxidation prior to the subsequent solder connection operation, is wettable by solder in the subsequent solder connection operation, and substantially dissolves in the solder in the subsequent solder connection operation without adverse effect on the solder joint between the electronic component and the through-hole, pad or land. A particular preferred protective material is gold, such as applied by deposition from immersion or electroless gold plating baths. The invention renders the so-treated areas readily susceptible to the soldering of components thereat, thereby avoiding the need for hot air solder levelling.