Bi2Ru2O7 Conductive Phase and its Effects on the Gauge Factor of Ru_based Thick-film Resistors

Author(s):  
Yiwu Ma ◽  
Jianqun Chen ◽  
Minqiang Li
2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000239-000244
Author(s):  
Andreas Heunisch ◽  
Victor de Seauve ◽  
Torsten Rabe

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.


1991 ◽  
Vol 14 (3) ◽  
pp. 163-173 ◽  
Author(s):  
M. Prudenziati ◽  
F. Sirotti ◽  
M. Sacchi ◽  
B. Morten ◽  
A. Tombesi ◽  
...  

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.


2006 ◽  
Vol 3 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Sonia Menot-Vionnet ◽  
Thomas Maeder ◽  
Claudio Grimaldi ◽  
Caroline Jacq ◽  
Peter Ryser

In this work, the properties (sheet-resistance, temperature coefficient and piezoresistance / gauge factor) and stability of thick-film resistors with low firing temperatures (525…650°C) are studied. To this end, two low-melting lead borosilicate glass compositions have been chosen, together with RuO2 as conductive filler. The effect on the properties and stability of composition and firing temperature is studied. The stability of the materials is quantified during high-temperature storage (annealing) at 250°C. These results show that reasonable resistive and piezoresistive properties, as well as stability, can be obtained even using lower processing temperatures compatible with deposition onto steel, titanium, aluminum and glass substrates.


1980 ◽  
Vol 6 (3-4) ◽  
pp. 247-251 ◽  
Author(s):  
A. Cattaneo ◽  
L. Pirozzi ◽  
B. Morten ◽  
M. Prudenziati

The effect of substrate type on the electrical properties of thick film resistors is determined. Five different substrates are used. The following properties are investigated: – thermal expansion, resistor profiles, resistance, TCR and resistor gauge factor. The resistors are physically inspected using X-ray diffractometry and electron probe analysis. This paper shows that conduction mechanism models for thick-film resistors generally need not take into account chemical and structural interactions with the substrate. However the effect of substrate on TCR values is significant for resistors exhibiting a large piezoresistive effect.


Author(s):  
Marko Hrovat ◽  
Darko Belavic ◽  
Janez Hole ◽  
Jena Cilensek ◽  
Goran Drazic

Author(s):  
Ye.Ya. Telnikov ◽  
O.G. Chernyshyn ◽  
O.M. Nedbailo ◽  
I.O. Khmara

The work is devoted to the solution of scientific and technical problems of creating granular resistive thick films used in the manufacture of metal-ceramic heating elements. Using the method of mechanosynthesis, particles of transition metal borides and aluminoborosilicate glass of complex chemical composition were obtained. The electrical and thermal properties of thick-film metal-ceramic heating elements with a resistive layer based on modified particles of a conductive material are studied. The heating elements of the new generation are made by the method of thick-film technology, which is widely used in microelectronics in the manufacture of hybrid electronic circuits. Structurally, the thick-film heater is a base (metal with a dielectric coating, ceramics, glass, glass), which is consistently applied through a mesh stencil resistive paste and a dielectric protective coating. Direct heat transfer from the heating film to the substrate of the heat remover, due to the very low thermal inertia of the design, provides a quick exit of the heating element to the operating temperature. This feature of heaters opens new opportunities for their special use. The resistive layer is a complex heterogeneous disordered system containing regions with a metallic conductivity and dielectric portions. The electrical conductivity in such systems is a superposition of the metallic type — in the conducting phase and the activation phase — through the interlayer between the particles. The layer plays the role of a potential barrier for current carriers and largely determines the predominance of one of the electromigration mechanisms. Its composition and properties are formed during the interaction of molten glass with oxide films of particles of the conductive phase and doping of the compositions. Obtaining composite particles of the conductive phase in the process of preparation and heat treatment of materials allows you to purposefully change the properties of the nanoscale interlayer between these particles, which leads to the possibility of creating a group of materials and heating elements based on them with a complex of new properties.


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