초록 ▼

This invention relates to a process which produces flat, distortion-free, zero-shrink, low-temperature co-fired ceramic (LTCC) bodies, composites, modules or packages from precursor green (unfired) laminates of three or more different dielectric tape chemistries that are configured in an uniquely or

This invention relates to a process which produces flat, distortion-free, zero-shrink, low-temperature co-fired ceramic (LTCC) bodies, composites, modules or packages from precursor green (unfired) laminates of three or more different dielectric tape chemistries that are configured in an uniquely or pseudo-symmetrical arrangement in the z-axis of the laminate.

대표청구항 ▼

What is claimed is: 1. A method to produce a distortion-free and camber-free asymmetrical low-temperature co-fired ceramic structure consisting essentially of one or more layers of low k glass-containing internal self-constraining tape, one or more layers of high k glass-containing internal self-co

What is claimed is: 1. A method to produce a distortion-free and camber-free asymmetrical low-temperature co-fired ceramic structure consisting essentially of one or more layers of low k glass-containing internal self-constraining tape, one or more layers of high k glass-containing internal self-constraining tape, and at least one layer of glass-containing primary tape wherein the dielectric constant of the low k tape is less than 8, the dielectric constant of the high k tape is greater than 8 and wherein each self-constraining tape can independently provide a self-constraining pressure-less assisted sintering LTCC assembly with the primary tape and wherein the self-constraining tapes are arranged to preserve structural symmetry regarding the class of self-constraining tapes as an entity with respect to the primary tape wherein the internal constraining tapes and the primary tape are laminated to form a compositionally asymmetrical laminate and wherein the assembly is thermally processed producing a structure exhibiting an interactive suppression of x,y shrinkage and wherein the glass composition of the low k glass-containing internal self-constraining tape comprises the following oxide constituents in the compositional range of SiO2 7-9, ZrO2 0-3, B2O3 11-14, BaO 7-23, MgO 3-9, La2O3 14-28, Li2O 0.5-2, P2O5 2-6, K2O 0.5-3, Cs2O 0-7, Nd2O3 28-34 in weight %. 2. The method of claim 1 wherein the dielectric constant of the primary tape is in the range of 7 to 9. 3. The method of claim 1 in which the tape layers are metallized in a planar and in an interconnection manner. 4. The method of claim 1 wherein the assembly is populated with surface mounted components. 5. The method of claim 1 wherein the glass of the constraining tapes initiates sintering to attain a rigid form before the onset of sintering of the primary tape. 6. The method of claim 1 wherein the internal constraining tapes and the primary tape comprise filler particles having a bimodal particle size distribution with D50 of the larger size particles being in the range of 1.5 to 3 microns and D50 of the smaller size particles being in the range of 0.3 to 0.8 microns. 7. The method of claim 1 wherein the glass of the primary tape comprises, based on total composition: SiO2 52-55, Al 2O3 12.5-14.5, B2O3 8-9, CaO 16-18, MgO 0. 5-5, Na2O 1.7-2.5, Li2O 0.2-0.3, SrO 0-4, K2O 1-2 in weight %. 8. A multilayer electronic circuit comprising a rigid form produced by the method of claim 1. 9. A multilayer electronic circuit comprising the rigid form of claim 1 wherein the internal constraining tape layers provide a capacitor function. 10. A distortion-free and camber-free asymmetrical low-temperature co-fired ceramic structure consisting essentially of one or more layers of low k glass-containing internal self-constraining tape, one or more layers of high k glass-containing internal self-constraining tape, and at least one layer of glass-containing primary tape wherein the dielectric constant of the low k tape is less than 8, the dielectric constant of the high k tape is greater tan 8 and wherein each self-constraining tape can independently provide a self-constraining pressureless assisted sintering LTCC assembly with the primary tape and wherein the self-constraining tapes are arranged to preserve structural symmetry regarding the class of self-constraining tapes as an entity with respect to the primary tape wherein the internal constraining tapes and the primary tape are laminated to form a compositionally asymmetrical laminate and wherein the assembly is thermally processed producing a structure exhibiting an interactive suppression of x,y shrinkage and wherein the glass composition of the low k glass-containing internal self-constraining tape comprises the following oxide constituents in the compositional range of SiO2 7-9, ZrO2 0-3, B 2O3 11-14, BaO 7-23, MgO 3-9, La2O3 14-28, Li2O 0.5-2, P2O5 2-6, K2O 0.5-3, Cs2O 0-7, Nd2O3 28-34 in weight % and wherein the glass of the constraining tapes initiates sintering to attain a rigid form before the onset of sintering of the primary tape. 11. The ceramic structure of claim 10 wherein the tape layers are metallized in a planar and in an interconnection manner. 12. The ceramic structure of claim 10 wherein the glass of the primary tape comprises, based on total composition: SiO2 52-55, Al2O3 12.5-14.5, B2O3 8-9, CaO16-18, MgO 0.5-5, Na2O 1.7-2.5, Li2O 0.2-0.3, SrO 0-4, K2O 1-2 in weight %.