Chip package with grease heat sink
The present invention relates to enhanced protection of the active surface and the bond wires or ball array of a microelectronic device, and to thermal management of the microelectronic device as it is packaged with a printed circuit board (PCB) or other substrate. The enhanced protection and thermal management are accomplished with a high-temperature thermal grease that is glob topped or encapsulated over the bond wires or ball array, and the active surface of the microelectronic device. The high-temperature thermal grease exchanges heat, particularly by conduction, away from the active surface of the microelectronic device as well as away from the bond wires.
1 . An integrated circuit (IC) chip package, comprising:
a substrate with an IC chip mounted thereon, wherein the substrate comprises a metallic heat sink and the IC chip has an active surface;
a grease in contact with the active surface of the IC chip; and
a container disposed upon the substrate, wherein the grease is enclosed within the container and the substrate, and wherein the container is in contact with the active surface of the IC chip.
2 . The IC chip package of claim 1 , further comprising an electric connector extending from the active surface, wherein the electrical connector is electrical communication with the IC chip, and wherein the electrical connect comprises a bond wire between the active surface and a printed circuit board disposed upon the heat sink.
3 . The IC chip package of claim 1 , wherein:
the container comprises a metal; and
the container contacts a printed circuit board disposed upon the substrate.
4 . The IC chip package of claim 1 , further comprising a flip-chip disposed over the active surface of the IC chip.
5 . The IC chip package of claim 4 , further comprising:
an electrical connector extending from the active surface, wherein:
the electrical connector is in electrical communication with the IC chip;
the electrical connector comprises a bond wire;
the bond wire is in contact with the grease;
the container comprises a metal; and
the container is disposed over the IC chip and the flip-chip.
6 . The IC chip package of claim 1 , further comprising:
an electrical connector extending from the active surface, wherein:
the electrical connector is in electrical communication with the IC chip; and
the container and the substrate together enclose the grease, the electrical connector, and the IC chip.
7 . The IC chip package of claim 1 , wherein the grease has a grease thermal conductivity, the container has a container thermal conductivity, and the grease thermal conductivity is less than the container thermal conductivity.
8 . The IC chip package of claim 1 , further comprising a vent hole in the container.
9 . The IC chip package of claim 1 , wherein the grease has a thermal conductivity in a range from about 2 Watts/m.K to about 5 Watts/m.K.
10 . The IC chip package of claim 1 , wherein the grease has a dielectric constant in a range from about 1.2 to about 10.
11 . The IC chip package of claim 1 , wherein the grease has a melting point in a range from about 190° C. to about 220° C.
12 . The IC chip package of claim 1 , wherein the grease has a weight loss about 100° C. after 30 days of less than about 0.15%.