Evaluation of Glass Frits for Development of Lead-Free Thick Film Resistor

2010 ◽  
Vol 2010 (1) ◽  
pp. 000752-000759
Author(s):  
Xudong Chen ◽  
W. Kinzy Jones
Keyword(s):  
Electrical Properties ◽  
Temperature Coefficient ◽  
Thick Film ◽  
Glass Frit ◽  
Lead Free ◽  
Temperature Coefficient Of Resistance ◽  
Film Resistor ◽  
Thick Film Resistor ◽  
Glass Compositions ◽  
Free Glass

Glass frit is a major component of thick film resistor (TFR) for the production of hybrid circuits. More than thirty commercial lead-free glass frits with different compositions have been evaluated for developing a lead-free thick film resistor that is compatible with typical industry thick film processing and has comparable electrical properties as the lead bearing counterpart. Two glass compositions were selected out of 33 candidates for preparation of RuO2 based TFR inks, which were screen printed on alumina substrates and fired at 850°C. The preliminary results of these resistors showed that the sheet resistance spanned from 400 ohms per square (Ω/□) to 0.4 mega-ohms per square (MΩ/□) with 5–15% RuO2 and the hot temperature coefficient of resistance (HTCR) fell in a range of ±350ppm/°C.

scholarly journals Thick Film Temperature Sensors Using Standard Pastes

1986 ◽  
Vol 12 (2) ◽  
pp. 91-101 ◽  
Author(s):  
I. Janoska ◽  
M. R. Haskard
Keyword(s):  
Aspect Ratio ◽  
Temperature Coefficient ◽  
Thick Film ◽  
Film Industry ◽  
Temperature Sensors ◽  
Electrical Characteristics ◽  
Temperature Coefficient Of Resistance ◽  
Film Resistor ◽  
Dielectric Layers ◽  
Thick Film Resistor

Standard thick film resistor pastes exhibit changes in their electrical characteristics when printed on top of dielectric layers. Of particular interest is the inherent change in their temperature coefficient of resistance. Simple temperature sensors were formed by deliberately printing thick film resistor pastes on top of larger area dielectric layers. Temperature tests carried out on these devices have shown that by selecting the correct paste combination and resistor aspect ratio stable, repeatable, temperature sensors with good linearity can be manufactured. A comparison is made of these sensors to other commercially available products currently used in the thick film industry.

scholarly journals The Relationship Between the Electrical Properties of Thick Film Resistors and the Thermal Expansion Coefficient of the Substrates

1987 ◽  
Vol 12 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Toshio Inokuma ◽  
Yoshiaki Taketa ◽  
Miyoshi Haradome
Keyword(s):  
Thermal Expansion ◽  
Electrical Properties ◽  
Low Temperature ◽  
Thick Film ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Film Resistor ◽  
Thick Film Resistor ◽  
The Relationship ◽  
Resistance Value

The temperature characteristics of RuO2-based thick film resistors on various substratcs having different thermal expansion coefficient have been investigated.It became clear that, if the thermal expansion coefficient of the substrate is larger than that of the thick film resistor, a compression is being exerted by the substrate on the as-fired resistor at low temperature. As temperature rises, the resistance value increases, and the TCR becomes positive.On the contrary, if the thermal expansion coefficient of the resistor is larger than that of the substrate, the as-fired resistor is being stretched by the substrate at low temperature. As temperature rises, the resistancc value decreases, and the TCR becomes negative.

Characterization of a New and Complete Lead-Free Thick Film Resistor System for the Hybrid Circuit Market

2015 ◽  
Vol 2015 (1) ◽  
pp. 000278-000285
Author(s):  
Michael A. Skurski ◽  
Marc H. LaBranche
Keyword(s):  
Thick Film ◽  
Thermal Ageing ◽  
Environmental Stability ◽  
Lead Free ◽  
Film Resistor ◽  
Characterization Study ◽  
Wide Range ◽  
Recent Developments ◽  
Gap Control ◽  
Thick Film Resistor

The move to lead-free thick film technology, including resistors does not necessarily mean a move away from performance. There have been many recent developments in the area of lead-free glasses, thick film dielectrics, and conductor materials. However, the development of lead-free resistor materials has been slower to enter the market. This slower evolution is due, in part, to the need to develop a series of discrete compositions that are compatible with each other and cover a wide range of resistance values. There can be 8–10 individual members in such a series. The primary goal of this development was to achieve resistor performance on par with, or superior to an existing and popular premium lead based resistor system. This paper describes a new series of lead-free thick film resistor compositions that cover a complete range of decade values from 1 Ohm/square to 10 MegOhms/square. Each member is compatible and blendable with adjacent members to cover all possible resistivity needs. This system provides excellent environmental stability of laser trimmed resistors, tight TCR gap control, a wide processing latitude, and minimal termination effects with a wide range of lead-free conductor metallurgies including Au, Ag, Ag/Pt, and Ag/Pd. In this paper, we report the results of a characterization study that includes 1000 hours of laser trim stability in 85°C/85%RH, thermal ageing at 150°C, room temperature ageing, and thermal cycle stability at −50°C +150°C. Electrical properties are presented and include Power Handling, Quan-tech Noise, and Electrostatic Discharge stability. In addition, this paper investigates and documents: resistor length effects, fire and refire sensitivity effects, thickness behavior, and the use of lead-free encapsulation.

Thermal Expansion and Laser Trim Stability of Ruthenium Based Thick Film Resistors on Alumina and on Multilayer Dielectric

1982 ◽  
Vol 1 (1) ◽  
pp. 24-27 ◽  
Author(s):  
I. Taitl
Keyword(s):  
Thermal Expansion ◽  
Thick Film ◽  
Chemical Structure ◽  
Coefficient Of Thermal Expansion ◽  
Ruthenium Dioxide ◽  
Theoretical Conclusion ◽  
Film Resistor ◽  
Thick Film Resistor ◽  
The Relationship ◽  
Multilayer Dielectric

Fired resistors exhibit variations which are minimised by abrasive and laser trimming. The latter may cause unstable behaviour which is further aggravated by thermal shock. The chemical structure of a thick film resistor is analysed with respect to mechanical stress, and the theoretical conclusion that the coefficient of thermal expansion of the resistor should be equal to or smaller than that of the substrate is verified experimentally. The thermal behaviour of ruthenium dioxide is examined and a range of CTE values are determined for materials of varying chemical composition. The relationship between CTE and post laser trimming stability is demonstrated on four thick film resistors which differ in thermal expansion. It is pointed out that formulations with high metallic content can absorb tensile stress by elastic deformation, thus minimising the formation or propagation of laser induced cracks.

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