QFN pre-molded leadframe having a solder wettable sidewall on each lead
First Claim
1. A method comprising:
- placing a leadframe on a bottom mold tool, the leadframe having a first plurality of recesses and a plurality of apertures, each of the first plurality of recesses having a size and a shape configured to receive one of the plurality of ridges, the leadframe also having a plurality of die pads and a plurality of leads;
placing a top mold tool on the leadframe, the top mold tool having a second plurality of recesses;
forming a first plurality of molding compound portions in the plurality of apertures and forming a second plurality of molding compound portions in the second plurality of recesses in a single molding step to form a pre-molded leadframe;
releasing the top mold tool and the bottom mold tool, the releasing including removing the pre-molded leadframe from the top mold tool and the bottom mold tool;
coupling a plurality of dies to each respective die pad of the pre-molded leadframe;
coupling the plurality of dies to the plurality of leads through a plurality of wires;
encapsulating the plurality of dies, the plurality of wires, and the second plurality of molding compound portions with an encapsulant; and
cutting the encapsulant, the leadframe and a metal layer to form a plurality of leadframe packages, each leadframe package having a first sidewall and a second sidewall with a portion of each sidewall covered by the metal layer.
2 Assignments
0 Petitions
Accused Products
Abstract
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.
6 Citations
19 Claims
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1. A method comprising:
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placing a leadframe on a bottom mold tool, the leadframe having a first plurality of recesses and a plurality of apertures, each of the first plurality of recesses having a size and a shape configured to receive one of the plurality of ridges, the leadframe also having a plurality of die pads and a plurality of leads; placing a top mold tool on the leadframe, the top mold tool having a second plurality of recesses; forming a first plurality of molding compound portions in the plurality of apertures and forming a second plurality of molding compound portions in the second plurality of recesses in a single molding step to form a pre-molded leadframe; releasing the top mold tool and the bottom mold tool, the releasing including removing the pre-molded leadframe from the top mold tool and the bottom mold tool; coupling a plurality of dies to each respective die pad of the pre-molded leadframe; coupling the plurality of dies to the plurality of leads through a plurality of wires; encapsulating the plurality of dies, the plurality of wires, and the second plurality of molding compound portions with an encapsulant; and cutting the encapsulant, the leadframe and a metal layer to form a plurality of leadframe packages, each leadframe package having a first sidewall and a second sidewall with a portion of each sidewall covered by the metal layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of molding a semiconductor die comprising:
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placing a leadframe in a mold; injecting molding compound into the mold in a top region of the leadframe to adhere to a top of the leadframe; injecting molding compound into the mold in a plurality of apertures of the leadframe to adhere to a bottom region of the leadframe; releasing the leadframe and the molding compound from the mold; coupling a plurality of dies to each respective die pad of the leadframe; coupling the plurality of dies to the leadframe through a plurality of wires; encapsulating the plurality of dies, the plurality of wires, and the second plurality of molding compound portions with an encapsulant; and cutting the encapsulant, the leadframe and the molding compound to form a plurality of leadframe packages. - View Dependent Claims (18, 19)
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Specification