Magnetic structures in integrated circuit packages

1. An integrated circuit (IC) package support, comprising:

a conductive line; and

a magnetic structure on a top surface and on side surfaces of the conductive line, wherein the magnetic structure has a rounded portion at a top surface of the magnetic structure.

2. The IC package support of claim 1 , wherein the magnetic structure includes magnetic particles embedded in a polymer matrix.

3. The IC package support of claim 1 , wherein the conductive line has a thickness between 20 microns and 30 microns.

4. The IC package support of claim 1 , wherein the magnetic structure tapers by a distance between 5 microns and 15 microns.

5. The IC package support of claim 1 , wherein the magnetic structure is a first magnetic structure, and the IC package support further includes:

a second magnetic structure at a bottom surface of the conductive line, wherein the second magnetic structure has rounded shoulder portions.

6. The IC package support of claim 1 , wherein the IC package support is a package substrate or an interposer.

7. The IC package support of claim 1 , wherein the conductive line and magnetic structure are part of an air core inductor (ACI).

8. An electronic assembly, comprising:

an integrated circuit (IC) package support, including a magnetic structure on a top surface and on side surfaces of a conductive line, wherein the magnetic structure has a rounded portion at a top surface of the magnetic structure.

9. The electronic assembly of claim 8 , wherein the IC package support further includes:

a first layer of dielectric material, wherein the magnetic structure is at least partially embedded in the first layer of dielectric material;

a conductive pad at least partially embedded in the first layer of dielectric material;

a second layer of dielectric material in contact with the top surface of the magnetic structure; and

a conductive via in conductive contact with the conductive pad, wherein the conductive via extends through the first layer of dielectric material.

10. The electronic assembly of claim 9 , wherein the conductive via also extends through the second layer of dielectric material.

11. The electronic assembly of claim 9 , wherein the conductive via does not extend through the second layer of dielectric material.

12. The electronic assembly of claim 11 , wherein the conductive via is a first conductive via, the IC package support further includes a second conductive via, the first conductive via is between the second conductive via and the conductive pad, and the second conductive via extends through the second layer of dielectric material.

13. The electronic assembly of claim 9 , wherein the first layer of dielectric material has a thickness between 35 microns and 75 microns.

14. The electronic assembly of claim 8 , wherein the IC package support further includes conductive contacts and the electronic assembly further includes one or more dies coupled to the conductive contacts.

15. The electronic assembly of claim 8 , wherein the IC package support is included in an IC package, the electronic assembly further includes a circuit board, and the IC package is coupled to the circuit board.

16. An integrated circuit (IC) package, comprising:

a package substrate including an air core inductor, wherein the air core inductor includes a conductive line and a magnetic structure on a top surface and on side surfaces of a conductive line, wherein the magnetic structure has a rounded portion at a top surface of the magnetic structure; and

one or more dies coupled to the package substrate.

17. The IC package of claim 16 , wherein the air core inductor is proximate to second-level interconnects of the package substrate.

18. The IC package of claim 16 , wherein the air core inductor is in an interior layer of the package substrate.