Bumped pad structure
A bumped solder pad and methods for adding bumps to a solder pad are provided. A substrate is provided having metal layer formed thereon and a solder pad formed from a portion of the metal layer. A surface treatment is applied to the solder pad. The surface treatment is patterned. The surface treatment is etched to produce at least one bump on the solder pad.
1. A method for adding at least one bump to a solder pad, the method comprising:
providing a substrate having a metal layer formed thereon and the solder pad formed from a portion of the metal layer;
applying and developing a photo-resist material to the solder pad;
applying a solder resist;
removing areas of the solder resist;
patterning the photo-resist material including selectively dissolving portions of the photo-resist material;
additively applying a surface treatment to the solder pad to produce the at least one bump on the solder pad;
removing remaining portions of the photo-resist material; and
applying a second surface treatment to the surface treatment, the second surface treatment comprising an organic solderability preservative.
2. The method according to claim 1 , wherein the surface treatment comprises a metal.
3. The method according to claim 1 , wherein the surface treatment comprises gold.
4. The method according to claim 1 , wherein the surface treatment comprises a nickel-gold alloy.
5. The method according to claim 1 , wherein applying the surface treatment to the solder pad comprises electroplating metal to the solder pad.
6. The method according to claim 1 , wherein additively applying the surface treatment comprises electroplating the surface treatment to the solder pad.
7. The method according to claim 1 , wherein patterning the photo-resist material exposes a portion of the solder pad.
8. The method according to claim 1 , the method further comprising:
exposing the photo-resist material to a transfer pattern; and
etching the metal layer.
9. A solder pad comprising:
a metal layer formed on a substrate to form the solder pad;
a photo-resist layer applied, developed, and pattered to the solder pad to selectively dissolve portions of the photo-resist material prior to one or more surface treatments;
a surface treatment additively applied to the metal layer, the surface treatment comprising at least one bump; and
a second surface treatment applied to the surface treatment, the second surface treatment comprising an organic solderability preservative.
10. The solder pad according to claim 9 , wherein the surface treatment comprises a metal.
11. The solder pad according to claim 9 , wherein the surface treatment comprises gold.
12. The solder pad according to claim 9 , wherein the surface treatment comprises a nickel-gold alloy.
13. The solder pad according to claim 9 , wherein additively applying the surface treatment to the solder pad comprises electroplating metal to the solder pad.
14. A solder pad comprising:
a metal layer means formed on a substrate means to form the solder pad;
a photo-resist means applied, developed, and pattered to the solder pad to selectively dissolve portions of the photo-resist material prior to one or more surface treatment means;
a surface treatment means additively applied to the metal layer means, the surface treatment means comprising at least one bump; and
a second surface treatment means applied to the surface treatment, the second surface treatment comprising an organic solderability preservative.
15. The solder pad according to claim 14 , wherein the surface treatment means comprises a metal.
16. The solder pad according to claim 14 , wherein the surface treatment means comprises gold.
17. The solder pad according to claim 14 , wherein the surface treatment means comprises a nickel-gold alloy.
18. The solder pad according to claim 14 , wherein additively applying the surface treatment means to the solder pad comprises electroplating metal to the solder pad.