Molding compound including a carbon nano-tube dispersion
Various embodiments disclose a molding compound comprising a resin, a filler, and a carbon nano-tube dispersion and methods of forming a package using the molding compound are disclosed. The carbon non-tube dispersion has a number of carbon nano-tubes with surfaces that are chemically modified by a functional group to chemically bridge the surfaces of the carbon nano-tubes and the resin, improving adhesion between the carbon nano-tubes and the resin and reducing agglomeration between various ones of the carbon nano-tubes. The carbon nano-tube dispersion achieves a low average agglomeration size in the molding compound thereby providing desirable electro-mechanical properties and laser marking compatibility. A shallow laser mark may be formed in a mold cap with a maximum depth of less than about 10 microns. Other apparatuses and methods are disclosed.
1. A semiconductor package, comprising:
a molding compound, including:
a resin; and
a number of carbon nano-tubes having surfaces that are chemically modified by a functional group, with reference to non-chemically modified carbon nano-tubes, the number of carbon nano-tubes with surfaces that are chemically modified by the functional group chemically bridge surfaces of the carbon nano-tubes and the resin to improve adhesion therebetween and reduce agglomeration between various ones of the number of carbon nano-tubes to an agglomeration size of less than about one micron, thereby increasing heat absorption of the molding compound.
2. The semiconductor package of claim 1 , wherein the chemical modification includes a silane coupling agent anchored at one end to surfaces of the number of carbon nano-tubes and an opposing end of the silane coupling agent being bonded to the functional group.
3. The semiconductor package of claim 1 , wherein the functional group is an epoxide group.
4. The semiconductor package of claim 1 , further comprising a filler material comprising silica.
5. The semiconductor package of claim 1 , wherein the resin comprises an epoxy.
6. The semiconductor package of claim 1 , wherein the resin comprises an organic polymer resin reinforced with glass fibers.
7. The semiconductor package of claim 1 , wherein the filler comprises between about 60 percent by weight to about 89 percent by weight of the molding compound.
8. The semiconductor package of claim 1 , wherein the number of carbon nano-tubes comprises about 0.001 percent by weight to about 0.05 percent by weight of the molding compound.
9. The semiconductor package of claim 1 , wherein a portion of the molding compound includes a mark on a surface of the semiconductor package, the mark having a depth of less than about 10 microns.
10. The semiconductor package of claim 1 , wherein the agglomeration size of the carbon nano-tubes of less than about one micron is an average agglomeration size.
11. The semiconductor package of claim 1 , wherein the molding compound comprises:
the resin being about 10 percent by weight to about 30 percent by weight;
the number of carbon nano-tubes being about 0.001 percent by weight to about 0.05 percent by weight; and
the filler being about 60 percent by weight to about 90 percent by weight.
12. The semiconductor package of claim 1 , further comprising at least one integrated circuit chip.
13. The semiconductor package of claim 12 , wherein the molding compound is formed as a mold cap over at least one surface of the integrated circuit chip.
14. The semiconductor package of claim 1 , wherein the number of carbon nano-tubes each have a diameter of about 1 nm to about 10 nm and a length of less than about 100 nm.
15. A package, comprising:
an integrated circuit chip; and
a mold cap covering the integrated circuit chip, the mold cap including a resin, a filler, and a carbon nano-tube dispersion having a number of carbon nano-tubes with surfaces that are chemically modified by a functional group, with reference to non-chemically modified carbon nano-tubes, the carbon nano-tubes with surfaces that are chemically modified by the functional group chemically bridge surfaces of the carbon nano-tubes and the resin to improve adhesion therebetween and reduce agglomeration between various ones of the number of carbon nano-tubes to an agglomeration size of less about than one micron, thereby increasing heat absorption of the molding compound, the number of carbon nano-tubes each having a diameter of about 1 nm to about 10 nm and a length of less than about 100 nm.
16. The package of claim 15 , wherein the chemical modification includes a silane coupling agent anchored at one end to surfaces of the number of carbon nano-tubes to result in C—O—Si covalent bonding at the surfaces of the carbon nano-tubes, an opposing end of the silane coupling agent being bonded to the functional group.
17. The package of claim 16 , wherein the chemical modification further includes 3-glycidoxypropyltlimethoxysilane.
18. The package of claim 15 , wherein a height of the mold cap over the integrated circuit chip is from about 50 microns to about 150 microns.
19. A molding compound, comprising:
a resin;
a filler; and
a carbon nano-tube dispersion having a number of carbon nano-tubes having surfaces that are chemically modified by a functional group, with reference to non-chemically modified carbon nano-tubes, the number of carbon nano-tubes with surfaces that are chemically modified by the functional group chemically bridge surfaces of the carbon nano-tubes and the resin to improve adhesion between the carbon nano-tubes and the resin and reduce agglomeration between various ones of the number of carbon nano-tubes to an average agglomeration size of less than about one micron, thereby increasing electrical resistance in the molding compound as compared with a number of agglomerated carbon nano-tubes, the number of carbon nano-tubes each having a diameter of about 1 nm to about 10 nm and a length of less than about 100 nm.
20. The molding compound of claim 18 , wherein the number of carbon nano-tubes is about 0.001 percent by weight to about 0.05 percent by weight.