Packaged semiconductor device with a lead frame and method for forming
A method of manufacturing a packaged semiconductor device includes patterning and plating silver nanoparticles in bonding areas of a lead frame, forming a hydrophilic group while oxidizing the silver nanoparticles, forming wire bonds on the silver nanoparticles, and encapsulating the wire bonds and the silver nanoparticles.
1. A method of manufacturing a packaged semiconductor device comprising:
depositing nanoparticles of conductive material on lead posts of a lead frame;
oxidizing the nanoparticles;
forming wire bonds between contacts on a semiconductor die and the nanoparticles on the lead posts.
2. The method of claim 1 , wherein the oxidizing the nanoparticles includes:
patterning photoresist with openings over the lead frame;
coating the nanoparticles with a layer of photoactive material; and
exposing the photoactive material to radiation.
3. The method of claim 2 , wherein:
the photoactive material is exposed to the radiation after the wire bonds are formed before the molding process.
4. The method of claim 1 , wherein the oxidizing the nanoparticles includes:
forming a hydrophilic group on the nanoparticles.
5. The method of claim 4 , wherein:
the nanoparticles are exposed to plasma after the wire bonds are formed.
6. The method of claim 1 , further comprising:
encapsulating the semiconductor die, nanoparticles and wire bonds in mold compound after the oxidizing the nanoparticles.
7. The method of claim 1 , wherein:
a size of the nanoparticles is between 10 and 500 nanometers.
8. The method of claim 1 , wherein:
the conductive material is silver.
9. The method of claim 8 , wherein:
the wire bonds are formed of one of a group consisting of: copper, silver, and gold.
10. The method of claim 1 , wherein:
the conductive material is silver, and
the plasma is one of a group consisting of: a mixture of hydrogen and nitrogen gas, and oxygen gas.
11. A packaged semiconductor device comprising:
a lead frame with a flag portion and lead posts surrounding the flag portion;
a semiconductor die mounted on the flag portion;
wire bonds between the lead posts and the semiconductor die; and
silver nanoparticles in contact with stitches of the wire bonds, wherein the silver nanoparticles are between the stitches and the lead posts, and wherein at least a portion of the silver nanoparticles are oxidized to form a hydrophilic group.
12. The packaged semiconductor device of claim 11 , further comprising:
mold compound encapsulating at least a portion of the lead posts, semiconductor die, and the wire bonds.
13. A packaged semiconductor device comprising:
a lead frame with a flag portion and lead posts surrounding the flag portion;
a semiconductor die mounted on the flag portion;
wire bonds between the lead posts and the semiconductor die; and
silver nanoparticles in contact with stitches of the wire bonds, wherein the silver nanoparticles are between the stitches and the lead posts wherein a size of the silver nanoparticles is between 10 and 500 nanometers.
14. The packaged semiconductor device of claim 11 , wherein the wire bonds are formed of copper.
15. A method of manufacturing a packaged semiconductor device comprising:
patterning and plating silver nanoparticles in bonding areas of a lead frame;
forming a hydrophilic group while oxidizing the silver nanoparticles;
forming wire bonds on the silver nanoparticles; and
encapsulating the wire bonds and the silver nanoparticles.
16. The method of claim 15 , wherein the oxidizing the nanoparticles includes:
coating the nanoparticles with a layer of photoactive material; and
exposing the photoactive material to radiation before the molding process.
17. The method of claim 15 , wherein the oxidizing the nanoparticles includes:
exposing the nanoparticles to plasma after the wire bonds are formed.
18. The method of claim 15 , wherein:
the wire bonds are formed of copper.
19. The method of claim 17 , wherein:
the plasma is one of a group consisting of: a mixture of hydrogen and nitrogen gas, and oxygen gas.
20. The packaged semiconductor device of claim 13 , wherein the wire bonds are formed of copper.