Systems and methods for patterning valve metals

A method of making a patterned high-capacitance-density valve metal device, the method comprising the following steps:

• providing a metal substrate;
• forming a nonporous portion of cold-sprayed metal by cold spraying the metal onto the metal substrate;
• forming a porous portion of cold-sprayed metal by cold spraying the metal onto the nonporous portion of cold-sprayed metal, resulting in the porous portion of cold-sprayed metal having a capacitance-density at least 10 μf/cc at a voltage of 400 V and a capacitance-density of at least 500 μf/cc at a voltage of 48 V;
• additively printing a dielectric material over at least a part of the metal substrate to form a build-up structure on the metal substrate and around the porous portion of cold-sprayed metal, the build-up structure comprising the dielectric material;
• drilling a first via passing through the build-up structure to the metal substrate;
• drilling a second via passing through the build-up structure to the metal substrate, the second via being physically spaced apart from the first via;
• and
• forming a metal lead frame on the metal substrate,
• wherein both the nonporous portion of cold-sprayed metal and the porous portion of cold-sprayed metal comprise one or more valve metals;
• the metal lead frame comprising:
• a first vertical interconnect disposed through the first via;
• a second vertical interconnect disposed through the second via;
• a first electrode termination disposed directly on and in physical contact with the first vertical interconnect;
• a second electrode termination disposed directly on and in physical contact with the second vertical interconnect, the second electrode termination being physically spaced apart from the first electrode termination;
• a third electrode termination disposed on the porous portion of cold-sprayed metal and physically spaced apart from the first electrode termination and the second electrode termination;
• and
• a fourth electrode termination disposed on the porous portion of cold-sprayed metal and physically spaced apart from the first electrode termination, the second electrode termination, and the third electrode termination,
• wherein the first vertical interconnect, the second vertical interconnect, the first electrode termination, the second electrode termination, the third electrode termination, and the fourth electrode termination all comprise metal,
• the method further comprising:
• forming an anodized electrode on the porous portion of cold-sprayed metal by anodizing a metal or dip-coating a conductive polymer, wherein the electrode is disposed under the third electrode termination and the fourth electrode termination;
• forming an encapsulating high-temperature insulating layer that encapsulates the metal substrate, the non-porous portion of cold-sprayed metal, the porous portion of cold-sprayed metal, the electrode, the first vertical interconnect, the second vertical interconnect, the first electrode termination, the second electrode termination, the third electrode termination, and the fourth electrode termination,
• wherein the encapsulating high-temperature insulating layer comprise a silicone, a polyimide, or an epoxy to provide a functional and reliable monolithic structure with high capacitance-density,
• the metal substrate comprising copper or aluminum,
• the nonporous portion of cold-sprayed metal comprising aluminum or tantalum,
• the porous portion of cold-sprayed metal comprising aluminum or tantalum,
• the dielectric material comprising polynorbornene, polyimide, polyether ether ketone, or epoxy,
• the first electrode termination, the second electrode termination, the third electrode termination, and the fourth electrode termination comprising printed silver or copper paste,
• the first via and the second via both being drilled vias created with a UV laser or a CO2 laser, and
• the build-up structure having an upper surface that is higher than an upper surface of the porous portion of cold-sprayed metal, such that a shortest distance between an upper surface of the metal substrate and the upper surface of the build-up structure is greater than a shortest distance between the upper surface of the metal substrate and the upper surface of the porous portion of cold-sprayed metal.