Aluminum clad copper structure of an electronic component package and a method of making an electronic component package with an aluminum clad copper structure
View Patent ↗An electronic component package that includes a package substrate having an aluminum bond pad formed from an aluminum clad copper structure. The aluminum clad copper structure is attached to a dielectric layer. An electronic component is attached to the substrate and includes a conductive structure electrically coupled to the aluminum bond pad. The aluminum bond pad, the electronic component, and at least a portion of the substrate are encapsulated with an encapsulant.
1. A method comprising:
attaching an electronic component to a package substrate, the package substrate includes an aluminum clad copper structure having an aluminum bond pad surface, the aluminum clad copper structure is attached to a dielectric layer of the package substrate;
electrically coupling a conductive structure of the electronic component to the aluminum bond pad surface;
encapsulating the electronic component and at least a portion of the package substrate with an encapsulant, the at least a portion including the aluminum bond pad surface;
wherein the aluminum clad copper structure is formed by attaching an aluminum clad copper layer to the dielectric layer and subsequently removing material of the aluminum clad copper layer.
2. The method of claim 1 wherein the aluminum clad copper structure includes an aluminum layer and a copper layer that are attached together under pressure.
3. The method of claim 1 wherein the electrically coupling includes wire bonding a wire including copper to the aluminum bond pad surface.
4. The method of claim 1 wherein the aluminum bond pad surface is a surface of an aluminum layer of the aluminum clad copper structure, the aluminum layer has a thickness of 10 microns or less.
5. The method of claim 1 wherein the package substrate includes a conductive material electrically coupled to the aluminum clad copper structure, wherein the conductive material is formed by plating after the aluminum clad copper layer is attached to the dielectric layer.
6. The method of claim 1 wherein a material of the aluminum clad copper layer is removed by forming a hole through the material of the aluminum clad copper layer and through the dielectric layer.
7. The method of claim 1 wherein aluminum of the aluminum clad copper layer is selectively removed from copper of the aluminum clad copper layer by an etch process with an etchant that is selective to aluminum and not selective to copper.
8. The method of claim 7 wherein after the etch process is performed, copper is plated on a copper surface of the aluminum clad copper layer from which aluminum was removed by the etch process.
9. The method of claim 8 wherein copper material is further removed from the package substrate after the copper is plated.
10. The method of claim 1 wherein the package substrate includes a conductive material electrically coupled to the aluminum clad copper structure, wherein the conductive material is formed by plating.
11. The method of claim 1 wherein the package substrate includes a plurality of vias in the dielectric layer, wherein a conductive material is located in the plurality of vias and is formed by a plating process after the attaching the aluminum clad copper layer to the dielectric layer.
12. The method of claim 1 further comprising:
forming a plurality of solder balls on a side of the package substrate opposite a side of the package substrate where the aluminum bond pad surface is located, wherein a solder ball of the plurality of solder balls is electrically coupled to the aluminum bond pad surface.
13. The method of claim 1 wherein the aluminum clad copper layer is formed by attaching an aluminum layer and a copper layer together by a rolling process.