Semiconductor package and method

1. A device comprising:

an integrated circuit die;

a first dielectric layer over the integrated circuit die;

a first metallization pattern extending through the first dielectric layer to electrically connect to the integrated circuit die;

a second dielectric layer over the first metallization pattern;

an under bump metallurgy extending through the second dielectric layer;

a third dielectric layer over the second dielectric layer and portions of the under bump metallurgy;

a conductive ring sealing an interface of the third dielectric layer and the under bump metallurgy, the conductive ring comprising a first reflowable material, the first reflowable material of the conductive ring contacting the third dielectric layer and the under bump metallurgy;

a conductive connector extending through the center of the conductive ring, the conductive connector electrically connected to the under bump metallurgy, the conductive connector comprising a second reflowable material; and

an intermetallic compound (IMC) disposed between the conductive ring and the conductive connector, the IMC comprising the first reflowable material and the second reflowable material.

2. The device of claim 1 , further comprising:

flux on the under bump metallurgy, the flux adjoining an inner sidewall of the conductive ring, the conductive connector being on the flux.

3. The device of claim 1 , wherein the conductive ring separates the conductive connector from the third dielectric layer.

4. The device of claim 1 , wherein the conductive ring extends through an opening in the third dielectric layer, the under bump metallurgy having a first radius, the opening having a second radius less than the first radius.

5. The device of claim 4 , wherein the conductive ring is around the opening, the conductive ring having an annular shape with an outer radius and an inner radius, a difference between the outer radius and the inner radius being from 30 μm to 50 μm.

6. The device of claim 5 , wherein the first radius of the under bump metallurgy is greater than the outer radius of the conductive ring.

7. The device of claim 5 , wherein the second radius of the opening is greater than the inner radius of the conductive ring and less than the outer radius of the conductive ring.

8. The device of claim 5 , wherein the first radius of the under bump metallurgy is greater than a third radius of the conductive connector.

9. The device of claim 1 , wherein the conductive ring extends along top surfaces of the third dielectric layer and the under bump metallurgy.

10. The device of claim 1 , wherein the conductive ring and the under bump metallurgy comprise different conductive materials.

11. A device comprising:

an integrated circuit die;

a through via adjacent the integrated circuit die;

an encapsulant around the through via and the integrated circuit die; and

a redistribution structure comprising:

a first dielectric layer disposed on the encapsulant;

a first metallization pattern on the first dielectric layer, the first metallization pattern extending through the first dielectric layer to electrically connect to the through via;

a second dielectric layer disposed on the first dielectric layer;

an under bump metallurgy on the second dielectric layer, the under bump metallurgy extending through the second dielectric layer to electrically connect to the first metallization pattern, the under bump metallurgy having a first radius;

a third dielectric layer disposed on the second dielectric layer; and

a conductive ring on the third dielectric layer, the conductive ring sealing an interface of the third dielectric layer and the under bump metallurgy, the conductive ring comprising a solder material, the solder material of the conductive ring contacting the third dielectric layer and the under bump metallurgy, the conductive ring having an outer radius, the outer radius being less than the first radius.

12. The device of claim 11 , further comprising:

a conductive connector on the under bump metallurgy and the conductive ring, the conductive ring separating the conductive connector from the third dielectric layer.

13. The device of claim 12 , further comprising:

a substrate electrically and physically connected to the redistribution structure by the conductive connector.

14. The device of claim 11 , wherein the conductive ring extends from a top surface of the third dielectric layer to a top surface of the under bump metallurgy.

15. A device comprising:

an integrated circuit die;

a first dielectric layer disposed over the integrated circuit die;

an under bump metallurgy having a first portion and a second portion, the first portion extending along a surface of the first dielectric layer, the second portion extending through the first dielectric layer, the under bump metallurgy being electrically connected to the integrated circuit die;

a second dielectric layer disposed over the under bump metallurgy and the first dielectric layer;

a reflowable annulus extending along and through the second dielectric layer, the reflowable annulus contacting the first portion of the under bump metallurgy, the reflowable annulus comprising a first reflowable material; and

a reflowable connector extending through the center of the reflowable annulus, the reflowable connector contacting the second portion of the under bump metallurgy, the first reflowable material of the reflowable annulus extending continuously between the reflowable connector and the second dielectric layer.

16. The device of claim 15 , wherein the reflowable annulus has an inner radius and an outer radius, the under bump metallurgy has a first radius, and the reflowable connector has a second radius, the first radius being greater than the outer radius, the second radius being greater than the inner radius.

17. The device of claim 16 , wherein a difference between the outer radius and the inner radius is from 30 μm to 50 μm.

18. The device of claim 15 , wherein the reflowable connector comprises a second reflowable material, and wherein the first reflowable material and the second reflowable material are different reflowable materials.

19. The device of claim 15 , wherein the reflowable annulus and the reflowable connector are distinct features, wherein the reflowable connector comprises a second reflowable material, and wherein the first reflowable material and the second reflowable material are the same reflowable material.

20. The device of claim 15 further comprising:

a first intermetallic compound (IMC) disposed between the reflowable connector and the under bump metallurgy;

a second IMC disposed between the reflowable connector and the reflowable annulus; and

a third IMC disposed between the first IMC and the second IMC.