Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
153 words
An interconnection substrate for electronic components formed by a sintered stack of sheets of dielectric material, at least some of which have conductive patterns thereon, said substrate having conductive emerging portions for connecting the terminals of the component(s) with at least one internal layer provided with conductive tracks providing interconnection between layers and with said emerging portions in accordance with a pre-established pattern, wherein the composition of the dielectric material comprises 95% to 98% Al 2 O 3 and a dielectric melting agent based on magnesia and titania having a composition corresponding to a ratio by weight of TiO 2 to MgO in the range of 1:0.5 to 1:6 thereby reducing the maximum sintering temperature required to a value lying in the range 1350° C. to 1450° C., and wherein the conductive patterns are made of a non-oxidizable metal which is not meltable at high temperatures or of an alloy of such metals.
Claim 2
Dependent Claim
153 words
An interconnection substrate for electronic components formed by a sintered stack of sheets of dielectric material, at least some of which have conductive patterns thereon, said substrate having conductive emerging portions for connecting the terminals of the component(s) with at least one internal layer provided with conductive tracks providing interconnection between layers and with said emerging portions in accordance with a pre-established pattern, wherein the composition of the dielectric material comprises 95% to 98% Al 2 O 3 and a dielectric melting agent based on magnesia and titania having a composition corresponding to a ratio by weight of TiO 2 to MgO in the range of 1:0.5 to 1:6 thereby reducing the maximum sintering temperature required to a value lying in the range 1350° C. to 1450° C., and wherein the conductive patterns are made of a non-oxidizable metal which is not meltable at high temperatures or of an alloy of such metals.
Claim 3
Dependent Claim
21 words
A substrate according to claim 1, wherein the melting agent contains TiO 2 and MgO in about equal amounts by weight.
Claim 4
Dependent Claim
19 words
A substrate according to claim 1, wherein the conductive patterns are made of palladium or of a silver-palladium alloy.
Claim 5
Dependent Claim
49 words
A substrate according to claim 1, wherein the layer-to-layer interconnections and the interconnections with the emerging portions are made by means of vias having a metallized coating based on a metal which is also not oxidizable and not meltable at high temperature or of an alloy of such metals.
Claim 6
Dependent Claim
44 words
A substrate according to claim 4, wherein the coating of the vias is made from a metallization ink impregnated with Al 2 O 3 , while the conductors patterns are made from an ink which is not impregnated with Al 2 O 3 .
Claim 7
Dependent Claim
37 words
A substrate according to claim 5 wherein the composition of the ink impregnated with Al 2 O 3 comprises 60% to 80% free metal and 2% to 5% Al 2 O 3 in an evanescent organic vehicle.
Claim 8
Dependent Claim
60 words
A substrate according to claim 6, wherein the composition of the ink which is impregnated with Al 2 O 3 includes a melting agent based on silica and on magnesia and suitable for reducing the firing temperature of the ink to a value which is equal to or slightly less than the temperature for firing the alumina of the substrate.
Claim 9
Dependent Claim
44 words
A substrate according to claim 7 wherein the relative proportion of melting agent and Al 2 O 3 in the ink are about one part by weight Al 2 O 3 , four parts by weight Si0 2 and three parts by weight MgO.
Claim 10
Dependent Claim
27 words
A substrate according to claim 5, wherein the ink impregnated with Al 2 O 3 is also used for providing rims at the ends of the vias.