Bowl shaped pad
Embodiments described herein provide techniques for forming an interconnect structure that includes a bowl shaped pad. Such embodiments can assist with improving interconnect joint reliability when compared to conventional pads that have a flat surface. An interconnect structure may comprise: a substrate (e.g., a semiconductor package, a PCB, etc.); and a metal pad over the substrate. The metal pad has a center region and an edge region. A thickness of the center region is smaller than a thickness of the edge region. A thickness of the center region may be non-uniform. The center region may have a bowl shape characterized by a stepped profile. The stepped profile is formed from metal layers arranged as steps. Alternatively, or additionally, the center region may have a bowl shape characterized by a curved profile. A pattern may be formed on or in a surface of the metal pad.
1. An interconnect structure, comprising:
a substrate; and
a metal pad over the substrate, wherein the metal pad has a center region and an edge region, wherein a thickness of the center region is smaller than a thickness of the edge region, wherein a thickness of the center region is non-uniform, wherein the center region is characterized by a stepped profile, wherein the stepped profile is formed from steps, and wherein each step comprises a horizontal surface and a vertical surface.
2. The interconnect structure of claim 1 , wherein the substrate is a printed circuit board.
3. The interconnect structure of claim 1 , wherein the substrate is a semiconductor package.
4. The interconnect structure of claim 1 , further comprising an interconnect joint on the metal pad.
5. An interconnect structure, comprising:
a first substrate;
a metal pad over the first substrate, wherein the metal pad has a center region and an edge region, wherein a thickness of the center region is smaller than a thickness of the edge region, wherein a thickness of the center region is non-uniform wherein the center region comprises steps having non-uniform thicknesses;
a second substrate over the metal pad; and
solder disposed in or on the metal pad, the solder coupling the first and second substrates to each other.
6. An interconnect structure, comprising:
a substrate; and
a metal pad over the substrate, wherein the metal pad has a center region and an edge region, wherein a thickness of the center region is smaller than a thickness of the edge region, wherein a pattern is formed in a surface of the metal pad, and wherein the pattern comprises one or more polygons.
7. The interconnect structure of claim 6 , wherein the substrate is a printed circuit board.
8. The interconnect structure of claim 6 , wherein the substrate is a semiconductor package.
9. The interconnect structure of claim 6 , further comprising an interconnect joint on the metal pad.
10. An interconnect structure, comprising:
a substrate; and
a metal pad over the substrate, wherein the metal pad has a center region and an edge region, wherein a thickness of the center region is smaller than a thickness of the edge region, wherein a pattern is formed in a surface of the metal pad, and wherein the pattern comprises a line segment.
11. The interconnect structure of claim 10 , wherein the line segment extends from the center region to the edge region.
12. The interconnect structure of claim 10 , wherein the line segment is a straight line segment.
13. The interconnect structure of claim 10 , wherein the line segment is a curved line segment.
14. The interconnect structure of claim 10 , wherein the substrate is a printed circuit board.
15. The interconnect structure of claim 10 , wherein the substrate is a semiconductor package.
16. The interconnect structure of claim 10 , further comprising an interconnect joint on the metal pad.