The evolution of spinel-based conductive phase in thick-film NTC thermistors

2006 ◽  
Author(s):  
Marko Hrovat ◽  
Janez Holc ◽  
Darko Belavic ◽  
Jena Cilensek
Keyword(s):  
Thick Film ◽  
Conductive Phase ◽  
Ntc Thermistors

Pressure-Assisted Sintering of Buried Thick Film Resistors in LTCC

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000239-000244
Author(s):  
Andreas Heunisch ◽  
Victor de Seauve ◽  
Torsten Rabe
Keyword(s):  
Thick Film ◽  
Electrical Resistance ◽  
Particle Distribution ◽  
Laser Diffraction ◽  
The Other ◽  
Sintering Process ◽  
Sheet Resistivity ◽  
Green Tape ◽  
Small Fluctuation ◽  
Conductive Phase

In this work, the effect of the pressure-assisted sintering process on buried thick film resistors integrated in LTCC multilayer has been studied. Four commercial resistor pastes with sheet resistivities between 10 kΩ and 10 MΩ/cm were analyzed. First they were characterized by SEM/EDX, XRD and Laser diffraction to determine composition and particle distribution. The pastes consist of isolating particles and of Ruthenium based particles that are supposed to build the conductive phase. The pastes were screen printed on LTCC green tape (DP 951) and buried in four layer laminates. Sintering was done in two ways, pressureless (PLS) and also pressure-assisted (PAS). The pressureless sintered resistors showed electrical resistance values roughly in the range of the nominal sheet resistivity and only relatively small fluctuation within one sample. The PAS samples on the other hand showed significantly higher resistances and larger deviations. The microstructure of the sintered resistors was again investigated by SEM and XRD. It seems that the resistivity is determined by the ratio of the two Ruthenium phases RuO2 and Pb2Ru2O6.5, where RuO2 has the higher conductivity. Buried resistors cannot be trimmed by a laser to adjust the resistance. But we discovered that a refiring step will reduce and normalize the resistivity of the PAS resistors significantly.

scholarly journals Size Effects in Ruthenium-Based Thick-Film Resistors: Rutile vs. Pyrochlore-Based Resistors

1991 ◽  
Vol 14 (3) ◽  
pp. 163-173 ◽  
Author(s):  
M. Prudenziati ◽  
F. Sirotti ◽  
M. Sacchi ◽  
B. Morten ◽  
A. Tombesi ◽  
...  
Keyword(s):  
Size Effect ◽  
Thick Film ◽  
Sheet Resistance ◽  
Firing Temperature ◽  
Size Effects ◽  
Conductive Phase ◽  
Lower Sheet ◽  
Lower Sheet Resistance

The size effect, namely the change of sheet resistance, Rsas a function of resistor length, has been investigated in layers whose conductive phase evolves from Pb-rich (Ru-deficient pyrochlores) to Pb2Ru2O6.5and finally to RuO2by increasing the firing temperature. It is found that Bi diffusion from the terminations is responsible for lower sheet resistance values in shorter resistors whatever the conductive phase is. On the contrary, Ag diffusion is responsible for lower sheet resistance values in shorter resistors only in the case of ruthenate conductive grains while the reverse is observed in RuO2-based layers. Size effect can be suppressed with Pt/Au-based terminations provided that no Bi is contained and with Au-metallorganic-based contact provided that the peak firing temperature is not too high.

Electrical properties of thick film NTC thermistors based on SrFe0.9Sn0.1O3−δ

2010 ◽  
Vol 12 (12) ◽  
pp. 2113-2119 ◽  
Author(s):  
Changlai Yuan ◽  
Xiufang Wu ◽  
Jingyue Huang ◽  
Xinyu Liu ◽  
Bo Li
Keyword(s):  
Electrical Properties ◽  
Thick Film ◽  
Ntc Thermistors

Fabrication and characterization of bulk and thick film perovskite NTC thermistors

2007 ◽  
Vol 24 (2) ◽  
pp. 14-18 ◽  
Author(s):  
J. Kulawik ◽  
D. Szwagierczak ◽  
B. Gröger ◽  
A. Skwarek
Keyword(s):  
Thick Film ◽  
Ntc Thermistors ◽  
Fabrication And Characterization

Development of the conductive phase in thick-film resistors: Two case studies

2008 ◽  
Author(s):  
Marko Hrovat ◽  
Darko Belavic ◽  
Janez Hole ◽  
Jena Cilensek ◽  
Goran Drazic
Keyword(s):  
Case Studies ◽  
Thick Film ◽  
Conductive Phase
Sign in / Sign up

Export Citation Format

Share Document