At&t Bell Laboratories

Western Electric Company, Inc.

William L Woods, Jr

Yinon Degani

Thomas Dixon Dudderar

Reed Scott Brown

Alex Michael Brzezinski

Robert S Zieles

Tinyee Jue

Described are a process for soldering at least one component having solder bumps to a substrate and a process for forming solder bumps on metal pads of an element, such as an IC package or substrate or both. The bumps are formed by stencil printing solder paste deposits on the metal pads, heating the solder paste deposits to reflow temperature of the solder in the solder paste deposits, and allowing the molten solder in each deposit to coalesce and during subsequent cooling solidify forming the bumps on the metal pads. The bumps are formed by conducting the stencil printing through apertures in an ultra-thick stencil, the apertures having trapezoidal crossection in the plane normal to the broad surfaces of the stencil with the top opening being smaller than the bottom opening and with the walls of the aperture sloping at an angle within a range of from 1 to 45 degrees from the vertical, the solder paste having a low tackiness and high metal loading, and the solder paste deposits covering an area which is equal to or exceeds an area of the metal pad in any ratio between 1.5:1 and 5:1. Bumps formed in this manner lead to the formation of reliable solder joints.

Surface mount solder assembly of leadless integrated circuit packages to

A telephone handset comprises elongated complementary upper and lower housing members that mate at their perimeters to form a hollow handset housing. The lower housing member includes a pair of spaced apart transducer receiving cavities, each being shaped to receive a cylindrical transducer surrounded by a flexible tubular gasket and form an acoustic seal therewith. Each gasket includes flanges around its circumference that project radially outward and in a direction opposite to the direction of insertion of the transducer/gasket assembly into its associated cavity. Such construction provides adequate mechanical retention between the transducer and the lower housing member and avoids the need for additional retaining hardware. The upper housing is joined to the lower housing using one or more pairs of side-mounted, interlocking hooks and latches. The upper housing further includes ribs, molded therein and positioned to maintain the transducers in place when it is joined with the lower housing.

Telephone handset construction

A tubular piece part (10) is tested to determine the rupture strength of the part when subject to lateral expansion (F) with respect to a bore (11) of the part. In one example, a tubular segmented collet (21) is placed in the bore of the part, and a tapered pin (23) is forced a predetermined distance into the collet (X) so as to expand the collet and part radially outward by a predetermined amount. The peak force required to so expand the collet is measured (57) so as to provide an indication of the rupture strength of the part, and particularly of the weld strength of a molded plastic tube having a radial weld line (W). In particular, this method provides an indication of the likelihood that the part will fail prematurely in the field, after subsequent assembly of the part with an insert member (17) that is force fit into the bore.

Methods and apparatus for testing rupture strength of tubular parts

Growing community of inventors

Keithville, LA, United States of America

William L Woods, Jr