Abstract: A patterned plasma treatment may be provided on the chip and/or the substrate to enhance the distribution of underfill material between the chip and the substrate. The underfill material is typically dispensed after the chip is electrically connected to the substrate. The chip may be electrically connected to the substrate by an array of solder bumps, as one example. The underfill material is draw into a gap between the chip and the substrate by a capillary action. The patterned plasma-treated area formed on the chip and/or on the substrate may cause greater capillary force on the underfill material, as compared to non-plasma-treated areas. Such patterned plasma-treatment area may be designed and laid out to provide for more or better control of the underfill distribution between the chip and substrate while forming a chip package.

Abstract: A patterned plasma treatment may be provided on the chip and/or the substrate to enhance the distribution of underfill material between the chip and the substrate. The underfill material is typically dispensed after the chip is electrically connected to the substrate. The chip may be electrically connected to the substrate by an array of solder bumps, as one example. The underfill material is draw into a gap between the chip and the substrate by a capillary action. The patterned plasma-treated area formed on the chip and/or on the substrate may cause greater capillary force on the underfill material, as compared to non-plasma-treated areas. Such patterned plasma-treatment area may be designed and laid out to provide for more or better control of the underfill distribution between the chip and substrate while forming a chip package.

Abstract: According to one embodiment of the invention, a system for forming ball grid array packages includes a substrate and a stencil engaging a first surface of the substrate. The stencil includes a center region having a first set of generally circular holes formed therein and a first outer region disposed radially outwardly from the center region having a second set of generally circular holes formed therein. The diameter of each of the generally circular holes of the second set is greater than the diameter of each of the generally circular holes of the first set. The system further includes a solder paste disposed outwardly from the stencil and a squeegee operable to spread the solder paste over the stencil to fill the first and second set of generally circular holes, thereby creating a plurality of solder paste regions.

Abstract: Apparatus and methods for removing excess solder from connections on electrical circuits is disclosed. The apparatus and methods comprise providing an enclosure in which the circuits with excess solder are heated to a temperature above the melting point of the excess solder. There is also provided a clamp or mounting device for securing the electrical circuits with the excess solder such that they can be spun up to a sufficient rotating speed to cause the excess solder to be spun off the connections by centrifugal force. The enclosure includes an annular solder collecting pan for collecting the excess solder as it is removed from the circuit board.