Leadless integrated circuit package having standoff contacts and die attach pad
View Patent ↗A leadless integrated circuit (IC) package comprising an IC chip mounted on a die attach pad and a plurality of electrical contacts electrically connected to the IC chip. The IC chip, the electrical contacts, and the die attach pad are all covered with a molding material, with portions of the electrical contacts and die attach pad protruding from a bottom surface of the molding material.
1. A leadless integrated circuit (IC) package, comprising:
a die attach pad having a top surface and a bottom surface, the die attach pad being a single discrete element having a center portion and a peripheral portion;
an IC chip mounted on the top surface of the die attach pad in the peripheral portion thereof, the top surface of the die attach pad having an area larger than an area of the IC chip mounted thereagainst;
a plurality of electrical contacts electrically connected to the IC chip;
a molding layer formed over the IC chip, the die attach pad, and the electrical contacts, the molding layer having a top part covering top portions of the electrical contacts and a bottom part through which the bottom surface of the die attach pad and bottom portions of the electrical contacts are exposed, the bottom part having an exposed surface disposed between the die attach pad and electrical contacts;
a ground ring on the top surface of the peripheral portion of the die attach pad;
wherein the bottom surface of the peripheral portion of the die attach pad is substantially flush with an exposed surface of the bottom part of the molding layer;
wherein the bottom portions of one or more of the plurality of electrical contacts extend out of the bottom part of the molding layer; and
wherein the bottom surface of the center portion of the die attach pad extends out of the bottom part of the molding layer by a distance less than a distance that the bottom portions of one or more of the electrical contacts extends out of the exposed surface of the bottom part of the molding layer.
2. The IC package of claim 1 , further comprising:
a ground ring on the top surface of the peripheral portion of the die attach pad.
3. The IC package of claim 2 , wherein the ground ring is disposed on portion of the die attach pad whose bottom surface is substantially flush with the bottom part of the molding layer.
4. The IC package of claim 1 , wherein the entire bottom surface of the center portion of the die attach pad is substantially flat.
5. The IC package of claim 1 , wherein the bottom surface of the center portion of the die attach pad has an area that is smaller than an area of the IC chip.
6. The IC package of claim 1 , wherein the bottom surface of the center portion of the die attach pad comprises a plurality of discrete protrusions.
7. The IC package of claim 1 , wherein the bottom surface of the center portion of the die attach pad has an area that is smaller than the area of the IC chip.
8. The IC package of claim 7 , wherein each of the electrical contacts has a top surface and a bottom surface, each of the bottom surfaces of the electrical contacts having an area that is smaller than an area of the top surfaces of the electrical contacts.
9. The IC package of claim 8 , further comprising a solder material formed on at least one of the electrical contacts and the die attach pad.
10. The IC package of claim 9 , wherein the solder material comprises a tin and lead solder alloy.