Stmicroelectronics Gmbh

Ela Mia Cadag

Aaron Cadag

Jefferson Sismundo Talledo

Rennier Rodriguez

Ian Harvey Arellano

Rammil Seguido

Aiza Marie Agudon

Moonlord Manalo

Ernesto Antilano, Jr

Lester Joseph Belalo

Frederick Ray Gomez

Ricky Calustre

Rohn Kenneth Serapio

The present disclosure is directed to leadless semiconductor packages with improved wettable flanks that encourage the formation of solder fillets when the leadless semiconductor package is mounted to a substrate. The solder fillets are consistently formed and are easily detectable by inspection systems, such as automated optical inspection (AOI) systems.

Method for manufacturing leadless semiconductor package with wettable flanks

Generally described, one or more embodiments are directed to semiconductor packages comprising a plurality of leads and methods of forming same. The plurality of leads include active leads that are electrically coupled to bond pads of a semiconductor die and thereby coupled to active components of the semiconductor die, and inactive leads that are not electrically coupled to bond pads of the semiconductor die. The active leads have surfaces that are exposed at a lower surface of the semiconductor package and forms lands, while the inactive leads are not exposed at the lower surface of the package.

Lead stabilization in semiconductor packages

A first side of a tapeless leadframe package is etched to form a ring shaped protrusion and a lead protrusion extending from a base layer. An integrated circuit die is mounted to tapeless leadframe package in flip chip orientation with a front side facing the first side. An electrical and mechanical attachment is made between a bonding pad of the integrated circuit die and the lead protrusion. A mechanical attachment is made between the front side of the integrated circuit die and the ring shaped protrusion. The integrated circuit die and the protrusions from the tapeless leadframe package are encapsulated within an encapsulating block. The second side of the tapeless leadframe package is then etched to remove portions of the base layer and define a lead for a leadframe from the lead protrusion and further define a die support for the leadframe from the ring shaped protrusion.

Tapeless leadframe package with exposed integrated circuit die

A semiconductor package formed utilizing multiple etching steps includes a lead frame, a die, and a molding compound. The lead frame includes leads and a die pad. The leads and the die pad are formed from a first conductive material by the multiple etching steps. More specifically, the leads and the die pad of the lead frame are formed by at least three etching steps. The at least three etching steps including a first etching step, a second undercut etching step, and a third backside etching step. The second undercut etching step forming interlocking portions at an end of each lead. The end of the lead is encased in the molding compound. This encasement of the end of the lead with the interlocking portion allows the interlocking portion to mechanically interlock with the molding compound to avoid lead pull out. In addition, by utilizing at least three etching steps the leads can be formed to have a height that is greater than the die pad of the lead frame. This differential in height reduces the span of wires used to form electrical connections within the semiconductor package. These reductions in the span of the wires reduces the chances of wire to wire and wire to die short circuiting because the wire sweep of the wires is reduced when the molding compound is placed.

Package with interlocking leads and manufacturing the same

The present disclosure is directed to a leadframe having a recess in a body of the leadframe to collect glue overflowing from the manufacturing process of coupling a semiconductor die to the leadframe. The recess extends beneath an edge of the semiconductor die so that any tendency of the glue to adhere to the semiconductor die is counteracted by a tendency of the glue to adhere to a wall of the recess and at least partially fill the volume of the recess. In addition, the recess for collecting adhesive may also form a mold lock on an edge of the leadframe, the mold lock providing a more durable connection between the leadframe and an encapsulant during physical and temperature stresses.

Modified leadframe design with adhesive overflow recesses

Leadless semiconductor package with wettable flanks

The present disclosure is directed to a leadframe package having solder wettable sidewalls that is formed using a pre-molded leadframe and methods of manufacturing the same. A metal plated leadframe with a plurality of recesses and a plurality of apertures is placed into a top and bottom mold tool. A molding compound is then formed in the plurality of recesses and apertures in the leadframe to form a pre-molded leadframe. A plurality of die and wires are coupled to the pre-molded leadframe and the resulting combination is covered in an encapsulant. Alternatively, a bare leadframe can be processed and the metal layer can be applied after encapsulation. A saw or other cutting means is used for singulation to form leadframe packages. Each resulting leadframe package has a solder wettable sidewall for improving the strength of solder joints between the package and a circuit board.

QFN pre-molded leadframe having a solder wettable sidewall on each lead

A semiconductor package formed utilizing a removable backside protective layer includes a leadframe, a die pad, leads and a molding compound around them. The first surface of the die pad and leads are exposed to an external environment by the plurality of recesses. The recesses are formed by coupling a removable backside protective layer to the leadframe before applying the molding compound. After the molding compound is applied and cured, the backside protective layer is removed to expose the first surface of the die pad and the first surfaces of the leads so the semiconductor package may be mounted within an electronic device. The removable backside protective layer protects the die pad and the leads from mold flashing and residue when forming the semiconductor package during the fabrication process.

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Calamba, Philippines

Ela Mia Cadag