Wafer-level chip-scale package structure utilizing conductive polymer
An integrated conductive polymer-solder ball structure is provided. The integrated conductive polymer-solder ball structure comprises a sputter seed layer applied to a wafer structure, one or more conductive polymer pad structures applied to the sputtered seed layer at locations on the wafer structure where one or more solder ball structures will be formed, an electroplating layer applied to portions of the one or more conductive polymer pad structures where a photoresist layer has been exposed, and a solder ball formed on each of the electroplating layers thereby forming the one or more solder ball structures.
1. A structure comprising:
a wafer structure;
a sputter seed layer applied to the wafer structure;
one or more conductive polymer pad structures applied to the sputtered seed layer at locations on the wafer structure where one or more solder ball structures will be formed;
an electroplating layer applied to portions of the one or more conductive polymer pad structures where a photoresist layer has been exposed; and
a solder ball formed on each of the electroplating layers thereby forming the one or more solder ball structures,
wherein each of the electroplating layers is comprised of gold and at least one of nickel, copper, titanium, titanium tungsten, chromium, chromium copper, or nickel vanadium.
2. A structure comprising:
a wafer structure including an oxide dielectric layer applied to a substrate layer, one or more aluminum pad structures applied to the oxide dielectric layer at locations on the wafer structure where one or more solder ball structures will be formed, and a hard oxide/nitride passivation dielectric layer applied to other locations on the wafer structure where the one or more solder ball structures will not be formed;
a sputter seed layer applied to the wafer structure;
one or more conductive polymer pad structures applied to the sputtered seed layer at the locations on the wafer structure where the one or more solder ball structures will be formed;
an electroplating layer applied to portions of the one or more conductive polymer pad structures where a photoresist layer has been exposed; and
a solder ball formed on each of the electroplating layers thereby forming the one or more solder ball structures.
3. The structure of claim 2 , wherein the one or more aluminum pad structures penetrate the oxide dielectric layer in order to provide an electrical conductive path to the substrate layer.
4. The structure of claim 2 , wherein the hard oxide/nitride passivation dielectric layer is also applied to outer portions of the one or more aluminum pad structures in order to provide structural support for the aluminum pad structures.
5. The structure of claim 4 , wherein the wafer structure further comprises:
a polyimide coating applied to the hard oxide/nitride passivation dielectric layer location on the wafer structure where the one or more solder ball structures will not be formed.
6. An integrated circuit that utilizes one or more polymer-solder ball structures, each integrated conductive polymer-solder ball structure comprising:
a wafer structure including an oxide dielectric layer applied to a substrate layer, one or more aluminum pad structures applied to the oxide dielectric layer at locations on the wafer structure where the one or more solder ball structures will be formed, and a hard oxide/nitride passivation dielectric layer applied to other locations on the wafer structure where the one or more solder ball structures will not be formed;
a sputter seed layer applied to the wafer structure;
one or more conductive polymer pad structures applied to the sputtered seed layer at the locations on the wafer structure where the one or more solder ball structures will be formed;
an electroplating layer applied to portions of the one or more conductive polymer pad structures where a photoresist layer has been exposed; and
a solder ball formed on each of the electroplating layers thereby forming the one or more solder ball structures.
7. The integrated circuit of claim 6 , wherein the one or more aluminum pad structures penetrate the oxide dielectric layer in order to provide an electrical conductive path to the substrate layer.
8. The integrated circuit of claim 6 , wherein the hard oxide/nitride passivation dielectric layer is also applied to outer portions of the one or more aluminum pad structures in order to provide structural support for the aluminum pad structures.
9. The integrated circuit of claim 8 , wherein the wafer structure further comprises:
a polyimide coating applied to the hard oxide/nitride passivation dielectric layer location on the wafer structure where the one or more solder ball structures will not be formed.