High performance system-on-chip using post passivation process
The present invention extends the above referenced continuation-in-part application by in addition creating high quality electrical components, such as inductors, capacitors or resistors, on a layer of passivation or on the surface of a thick layer of polymer. In addition, the process of the invention provides a method for mounting discrete electrical components at a significant distance removed from the underlying silicon surface.
1 . A circuit substrate comprising:
a silicon substrate;
a dielectric layer over said silicon substrate;
a first metal layer over said dielectric layer, wherein said first metal layer comprises gold;
an insulating layer over said first metal layer and said dielectric layer;
a second metal layer over said insulating layer, wherein said second metal layer comprises gold;
a polymer layer over said second metal layer and said insulating layer, wherein said polymer layer has a thickness between 2 and 150 micrometers; and
a coil on said polymer layer, and over said second metal layer, said insulating layer, said first metal layer and said dielectric layer, wherein said coil comprises electroplated gold.
2 . The circuit substrate of claim 1 , wherein said first polymer layer comprises polyimide.
3 . The circuit substrate of claim 1 , wherein said first polymer layer comprises benzocyclobutene (BCB).
4 . The circuit substrate of claim 1 , wherein said insulating layer comprises oxide layer.
5 . The circuit substrate of claim 1 , wherein said coil comprises a spiral coil.
6 . The circuit substrate of claim 1 , wherein said first metal layer comprises electroplated gold.
7 . A method of forming a circuit substrate, comprising:
providing a silicon substrate;
forming a dielectric layer over said silicon substrate;
forming a first metal layer over said dielectric layer, wherein said forming said first metal layer comprises an electroplating gold process;
forming an insulating layer over said dielectric layer and said first metal layer;
forming a second metal layer over said insulating layer layer, wherein said forming said second metal layer comprises depositing a gold layer;
forming a polymer layer over said second metal layer and said insulating layer, wherein said polymer layer has a thickness between 2 and 150 micrometers, and wherein said forming said polymer layer comprises multiple coating and curing;
forming a coil on said polymer layer and over said second metal layer, said insulating layer, said first metal layer and said dielectric layer, wherein said forming said coil comprises an electroplating gold process.
8 . The method of claim 7 , wherein said first polymer layer comprises polyimide.
9 . The method of claim 7 , wherein said first polymer layer comprises benzocyclobutene (BCB).
10 . The method of claim 7 , wherein said insulating layer comprises oxide layer.
11 . The method of claim 7 , wherein said coil comprises a spiral coil.
12 . The method of claim 7 , wherein said first metal layer comprises electroplated gold.