Texas Instruments Corporation

Joseph S Antao

Troy D Moore

James E Loveless

Dennis M Botkin

Thomas J Difloria

Michael D Glucksman

The invention is to a method for forming solder contact balls (12) for a ball grid array semiconductor device. A solder sheet (15) is formed having solder elements (18) extending out at least one side of the solder sheet (15). The solder sheet is placed over and aligned on a semiconductor package (50) on which solder balls (12) are to be electrically connected to contact areas (51). The solder sheet (15) is aligned with one solder element (18) over each contact area (51). The package (50) and solder sheet (15) is heated to cause the solder elements (18) on the solder sheet (15) to separate and reflow such that the surface tension of the reflowed solder of each solder element (18) forms a solder ball (12) over a contact area (51).

Method of forming ball grid array contacts

A lead conditioning system (10) provides an offset conditioner (12), a planarity conditioner (14) and a tweeze conditioner station (16), a centering station (18), a transport assembly (20), a cabinet (22) having an input station (24) and an output station (26), and a control electronic control apparatus (28). Offset conditioner (12) conditions the offset spacing between leads of a gull-wing semiconductor device by shifting the leads axially in both directions and returning the leads to a center position according to a predetermined specification. Likewise, planarity conditioner station (14) deforms the leads of the semiconductor device so that the leads are essentially upright then repositions the leads by exerting forces downwardly on the tips of the leads so that the tips of the leads of the semiconductor device are essentially shifted to a coplanar position according to a predetermined specification. Offset conditioner (12) features a self-centering device with blades which accurately center the semiconductor device when the self-centering device is lowered thereover. Offset conditioner (12) also features a blade unit which is constructed with successive laminations of steel for enhanced strength and durability of the blades despite the thin width thereof.

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Allen, TX, United States of America

Joseph S Antao