Cofiring of LTCC multilayer assemblies with integrated NTC thermistor temperature sensor layers. Issue 19 (1st October 2021)

• Record Type: Journal Article
• Authors: Reimann, Timmy; Barth, Stefan; Capraro, Beate; Bartsch, Heike; Töpfer, Jörg
• Is Part Of: Ceramics international. Volume 47:Issue 19(2021)
• Page Start: 27849
• Page End: 27853
• Publication Date: 2021-10-01
• Subjects: Thermistors -- Low temperature cofired ceramics -- Spinels -- LTCC modules -- Thick films -- Embedded passives; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.06.213
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: We have studied the integration of Ni–Co–Zn–Mn spinel NTC thermistor layers into LTCC multilayer modules. Sintering of the cubic spinel Ni0.5 Co0.5 Zn0.75 Mn1.25 O4 with addition of 3 wt% Bi2 O3 additive at 900 °C resulted in samples with 96% density and with good electrical performance. Thermistor spinel tapes, fabricated using doctor blade tape casting, were stacked with layers of a commercially available low-k dielectric LTCC tape, and cofired at 900 °C. Free or constrained cofiring did not give crack-free multilayer samples. Thermistor layers were then integrated combining the commercial LTCC tape with a Zn titanate-based tape in one multilayer laminate, and error-free multilayer samples with a room-temperature resistivity of ρ298 = (2, 9 ± 0.08) kΩcm and a thermistor constant of B = (4280 ± 200) K were obtained. This demonstrates the possibility of cofiring of functional ceramic and low-k LTCC tapes and shows the potential of NTC spinel thermistor layers as temperature sensors integrated in complex LTCC multilayer architectures.