Quick turn around fabrication process for packaging substrates and high density cards

A structure for packaging one or more high density Integrated Circuit chips by creating an interconnect substrate overlying a metal substrate, said structure containing:

• a metal substrate having a first surface and a second surface;
• a first layer of dielectric with a thickness between about 0.5 mils and 3 mils deposited over said first surface of said metal substrate;
• one or more interconnect layers deposited over said first layer of dielectric thereby forming an interconnect substrate said interconnect layer being patterned using maskless exposure equipment;
• said interconnect substrate having a first and a second surface whereby said second surface of said interconnect substrate essentially abuts to said first surface of said metal substrate;
• a coating over said first surface of said interconnect substrate serving as a solder mask;
• metal pads within said first surface of said interconnect substrate thereby providing points of electrical access to said first surface of said interconnect substrate;
• one or more openings created in the second surface of said metal substrate by masking and etching said second surface of said metal substrate thereby furthermore creating exposed portions of said first layer of dielectric within said openings created in the second surface of said metal substrate;
• openings selectively created in said exposed first layer of dielectric thereby providing points of electrical access and heat transfer to said second surface of said interconnect substrate;
• points of electrical connections to said second surface of said interconnect substrate selectively created in said first layer of dielectric;
• and
• subdividing said metal substrate into individual IC chip substrates or interconnect cards whereby bare semiconductor devices and/or packaged semiconductor devices are attached to said second surface of said interconnect substrate and make electrical contacts through said dielectric openings.