Compressive pedestal for microminiature connections
AssigneeHughes Aircraft Company
InventorNils E. Patraw
Life of this patent
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Abstract
Apparatus is disclosed for providing microelectronic, intra-chip and chip-to-chip interconnections in an ultra-dense integrated circuit configuration. Compressive pedestals 20 are used to form spring-loaded electrical and mechanical interconnections to conductive terminals on a chip interface mesa and chip assembly 28 in order to form a large multi-chip array 23 on an interconnection substrate 24. Methods are also disclosed for fabricating the compressive pedestals 20.
Claims5
A method of fabricating an upstanding electrical terminal coupled to a conductive pathway upon a surface of a substrate, comprising the steps of:
- applying a layer of photoresist to a surface of a substrate;
- processing the photoresist layer in order to create an opening within the photoresist layer such that a portion of a conductive pathway upon the underlying surface is exposed;
- filling the opening with a supersaturated solution comprised of KCl such that the filled opening has a positive meniscus;
- drying the supersaturated solution of KCl such that the shape of the positive meniscus is maintained;
- removing the photoresist layer;
- depositing an electrically conductive layer over the dried KCl such that the conductive layer has a convex upper surface region and a plurality of downwardly extending leg portions, each leg portion being conductively coupled through a wider foot portion to the pathway;
- and removing the dried KCl such that the deposited electrically conductive layer is left upstanding upon the substrate.
A method of fabricating an upstanding electrical terminal coupled to a conductive pathway upon a surface of a substrate, comprising the steps of:
- applying a coating comprised of a polyimide to a surface of a substrate;
- curing the polyimide coating;
- applying a first photoresist layer over the polyimide coating;
- processing the first photoresist layer and the polyimide coating to create an opening within the polyimide coating such that a portion of a conductive pathway upon the underlying surface is exposed;
- removing the first photoresist layer;
- filling the opening within the polyimide coating with photoresist such that the filled opening has a positive meniscus;
- removing the polyimide coating;
- depositing an electrically conductive layer over the photoresist such that the conductive layer has a convex upper surface region and a plurality of downwardly extending leg portions, each leg portion being conductively coupled through a wider foot portion to the pathway;
- and
- dissolving the photoresist such that the deposited electrically conductive layer is left upstanding upon the substrate.
Dependencies are inferred from the claim text.