Glass-ceramic structures and sintered multilayer substrates thereof with circuit patterns of gold, silver or copper
AssigneeInternational Business Machines Corporation
InventorsAnanda H. Kumar, Peter W. McMillan, Rao R. Tummala
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Abstract
Sintered glass-ceramic substrates containing multi-level, interconnected thick-film circuit patterns of highly conductive metals such as gold, silver or copper are provided which can be fired in air (for gold and silver) or in neutral atmospheres (for copper) at temperatures below the melting points of these metals. This has been made possible by the discovery that finely divided powders of certain glasses described herein sinter to essentially zero porosity at temperatures below 1000.degree. C. while simultaneously maturing to glass-ceramics of low dielectric constant, high flexural strength and low thermal expansivity.
Claims8
A glass ceramic article with the internal mass thereof comprising:
- a homogenous distribution of a microstructure of a pervasive continuous connected network of 2 to 5 .mu.m crystallites selected from the group consisting of (A) .beta.-spodumene with the interstices of said network thereof occupied by residual glass having dispersed therein discrete secondary 1 to 2 .mu.m crystallites of lithium metasilicate and (B) alphacordierite with the interstices thereof occupied by residual glass having dispersed therein secondary 1 to 2 .mu.m crystallites of clinoestatite, with said article being substantially non-porous throughout the volume thereof;
- and
- an electrical conductor pattern embedded in said article having terminal portions terminating at at least one surface of said article for electrical connection thereto.
A ceramic article with the internal mass thereof comprising:
- a homogenous distribution of a microstructure of a pervasive continuous connected network of 2 to 5.mu.m crystallites selected from the group consisting of (A) .beta.-spodumene with the interstices of said network thereof occupied by residual glass having dispersed therein discrete secondary 1 to 2 .mu.m crystallites of lithium metasilicate and (B) alphacordierite with the interstices of said network thereof occupied by residual glass having dispersed therein secondary 1 to 2 .mu.m crystallites of clinoenstatite, with said article being substantially non-porous throughout the volume thereof;
- and
- at least two spaced and interconnected levels of electrical conductor patterns embedded in said article and having terminal portions extending to at least one surface of said article for electrical connection to an external electrical circuit.
Dependencies are inferred from the claim text.