Patent ID: 7068492
Filing Date: 2006-06-27
Classification: B32B,C03C,C04B,H01L,H05K

Abstract:
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 SiO 2 7–9, ZrO 2 0–3, B 2 O 3 11–14, BaO 7–23, MgO 3–9, La 2 O 3 14–28, Li 2 O 0.5–2, P 2 O 5 2–6, K 2 O 0.5–3, Cs 2 O 0–7, Nd 2 O 3 28–34 in weight %.