Connector design for packaging integrated circuits
A device includes a top dielectric layer having a top surface. A metal pillar has a portion over the top surface of the top dielectric layer. A non-wetting layer is formed on a sidewall of the metal pillar, wherein the non-wetting layer is not wettable to the molten solder. A solder region is disposed over and electrically coupled to the metal pillar.
1. A device comprising:
a top dielectric layer having a top surface;
a metal pillar comprising a portion over the top surface of the top dielectric layer;
a metal cap over the metal pillar, wherein a portion of the metal cap is aligned to the metal pillar, and wherein the metal cap has a lateral size greater than a lateral size of the metal pillar;
a first non-wetting layer on a sidewall of the metal cap, wherein the first non-wetting layer is not wettable to molten solder; and
a solder region over and electrically coupled to the metal cap.
2. The device of claim 1 further comprising a second non-wetting layer on a sidewall of the metal pillar, wherein the second non-wetting layer is not wettable to molten solder, and wherein the second non-wettable layer comprises materials for forming the metal pillar and an element selected from the group consisting essentially of nitrogen, oxygen, and combinations thereof.
3. The device of claim 2 , wherein the metal cap and the metal pillar comprise different materials, and wherein the second non-wetting layer does not extend between the metal cap and the metal pillar.
4. The device of claim 1 , wherein the first non-wetting layer does not extend between the metal cap and the solder region.
5. The device of claim 1 wherein the first non-wettable layer comprises materials of the metal cap and an element selected from the group consisting essentially of nitrogen, oxygen, and combinations thereof.
6. The device of claim 1 , wherein the top dielectric layer and the metal pillar are comprised in a device die, wherein the device further comprises a package component bonded to the device die through the solder region.
7. A device comprising:
a metal pillar comprising a portion over a top surface of a top dielectric layer;
a metal cap over the metal pillar, wherein a portion of the metal cap is aligned to the metal pillar, and wherein the metal cap has a lateral size greater than a lateral size of the metal pillar;
a first non-wetting layer on a sidewall of the metal cap, wherein the first non-wetting layer is not wettable to molten solder; and
a solder region over and electrically coupled to the metal cap, wherein the first non-wetting layer does not extend between the metal cap and the solder region.
8. The device of claim 7 further comprising a second non-wetting layer on a sidewall of the metal pillar, wherein the second non-wetting layer is not wettable to molten solder, and wherein the second non-wettable layer comprises materials for forming the metal pillar and an element selected from the group consisting essentially of nitrogen, oxygen, and combinations thereof.
9. The device of claim 8 , wherein the metal cap and the metal pillar comprise different materials, and wherein the second non-wetting layer does not extend between the metal cap and the metal pillar.
10. The device of claim 7 , wherein the first non-wettable layer comprises materials of the metal cap and an element selected from the group consisting essentially of nitrogen, oxygen, and combinations thereof.
11. The device of claim 7 , wherein the top dielectric layer and the metal pillar are comprised in a device die, wherein the device further comprises a package component bonded to the device die through the solder region.