A-Sat Corporation

Nelson Fan

Neil Mclellan

A leadless plastic chip carrier is constructed by half etching one or both sides of the package design onto a leadframe strip. After wire bonding and molding, a further etching is performed to isolate and expose contact pads. Singulation of individual chip packages from the leadframe strip may then be performed by saw singulation or die punching.

Leadless plastic chip carrier with etch back pad singulation

A leadless integrated circuit package, comprising an exposed semiconductor die and contact pads embedded in an over mold, and wires interconnecting the semiconductor die and contact pads. The leadless integrated circuit package is fabricated by etching a leadframe strip to define a plurality of contact pads; attaching an adhesive film to a bottom surface of the leadframe strip; mounting a semiconductor die to the adhesive film intermediate respective pairs of the contact pads; wire bonding the semiconductor die to the respective pairs of contact pads; encapsulating a top surface of the leadframe strip in a molding material; removing the adhesive film from the bottom surface of the leadframe strip for exposing the contact pads and the semiconductor die; solder plating the exposed bottom surface, and singulating the leadless integrated circuit package from the leadframe strip, whereby the adhesive film holds the semiconductor die in place prior to the encapsulating step, and prevents the molding material from contacting the exposed contact pads.

Exposed die leadless plastic chip carrier

Leadless plastic chip carriers are formed from a matrix of lead frames provided in a section of a metal strip. Each lead frame in the matrix includes a die-attach pad and multiple leads disposed in close proximity to the die-attach pad. After a semiconductor die is attached to each of the die-attach pad and wire-bonded, the leadless plastic chip carriers are formed by providing a plastic encapsulation which exposes the bottom sides of the die-attach pad and the leads. The bottom sides of the leads serve as solder pads to be used for attaching the leadless plastic chip carrier to a printed circuit board.

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Hong Kong, China

Nelson Fan