scholarly journals Recent advances in NTC thick film thermistor properties and applications

2017 ◽  
Vol 30 (3) ◽  
pp. 267-284 ◽  
Author(s):  
Obrad Aleksic ◽  
Pantelija Nikolic
Keyword(s):  
Thick Film ◽  
Heat Loss ◽  
Water Flow ◽  
Weight Ratio ◽  
Glass Frit ◽  
Thermal Sensors ◽  
Electrical Measurements ◽  
Sensor Applications ◽  
Zno Powders ◽  
Electrical Components

An introduction to thermal sensors and thermistor materials is given in brief. After that novel electrical components such as thick film thermistors and thermal sensors based on them are described: Custom designed NTC thermistor pastes based on nickel manganite NiM2O4 micro/nanostructured powder were composed and new planar cell-based (segmented) constructions were printed on alumina. The thick film segmented thermistors were used in novel thermal sensors such as anemometers, water flow meters, gradient temperature sensor of the ground, and other applications. The advances achieved are the consequence of previous improvements of thermistor material based on nickel manganite and modified nickel manganite such as Cu0.2Ni0.5Zn1.0Mn1.3O4 and optimization of thick film thermistor geometries for sensor applications. The thermistor powders where produced by a solid state reaction of MnCO3, NiO, CuO, ZnO powders mixed in proper weight ratio. After calcination the obtained thermistor materials were milled in planetary ball mils, agate mills and finally sieved by 400 mesh sieve. The powders were characterized by XRD and SEM. The new thick film pastes where composed of the powders achieved, an organic vehicle and glass frit. The pastes were printed on alumina, dried and sintered and characterized again by XRD, SEM and electrical measurements. Different thick film thermistor constructions such as rectangular, sandwich, interdigitated and segmented were printed of new thermistor pastes. Their properties such as electrical resistance of the thermistor samples where mutually compared. The electrode effect was measured for all mentioned constructions and surface resistance was determined. It was used for modeling and realizations of high, medium and low ohmic thermistors with different power dissipation and heat loss. Finally all the results obtained lead to thermal sensors based on heat loss for measuring the air flow, water flow, temperature gradient and heat transfer from the air to the ground.

Optimization and Application of NTC Thick Film Segmented Thermistors

2013 ◽  
Vol 543 ◽  
pp. 491-494 ◽  
Author(s):  
Maria Vesna Nikolic ◽  
Obrad.S. Aleksic ◽  
Branka M. Radojcic ◽  
Miloljub D. Lukovic ◽  
Nenad Nikolic ◽  
...  
Keyword(s):  
Thick Film ◽  
Water Flow ◽  
Water Flow Rate ◽  
Input Voltage ◽  
Glass Frit ◽  
Water Current ◽  
Thermal Sensor ◽  
Layer By Layer ◽  
Reduced Dimensions ◽  
Water Mains

NTC thermistor paste for printing thermal sensors on alumina was formed of very fine Ni0.5Cu0.2Zn1.0Mn1.3O4 thermistor powder obtained by a combined mechanical activation/thermal treatment process, organic vehicle and glass frit. Sheet resistivity was measured using an R-test matrix and it was much lower than the value determined for pure nickel manganite thermistors. The thermistor exponential coefficient was calculated from the R[ diagram measured in the temperature range-30 to +120°C in a climatic chamber. Thick film segmented thermistors with reduced dimensions (optimized construction) were printed sequentially layer by layer, dried and fired at 850°C/10 min in air. Electrodes were printed of PdAg conductive and solderable paste. The samples obtained were characterized by electrical and thermal measurements. The obtained NTC segmented thermistors with reduced dimensions were applied in a thermal sensor for water flow in the water mains. It contained a cold thermistor for measuring input water temperature and a self-heating thermistor for measuring the dependence of water current on water flow rate at a set input voltage power. Initial measurements show that the thermal sensor system requires a low input voltage power making it much easier and safer for operation.

Modeling of the Heat Loss in a Thermal Sensor for Water Made of NTC Thick Film Segmented Thermistors

2013 ◽  
Vol 543 ◽  
pp. 334-337 ◽  
Author(s):  
Miloljub D. Lukovic ◽  
Maria Vesna Nikolic ◽  
Branka M. Radojcic ◽  
Obrad S. Aleksić
Keyword(s):  
Water Temperature ◽  
Thick Film ◽  
Heat Loss ◽  
Water Flow ◽  
Heat Balance ◽  
Heating Temperature ◽  
Balance Equations ◽  
Flow Meter ◽  
Exponential Factor ◽  
Self Heating

NTC thick film segmented thermistors were realized by screen printing of a low resistivity paste and conductive PdAg paste printed for electrodes. Two thick film thermistors as thermal sensors were placed in plastic tube housing connected to the water mains to form a calorimetric type of flow-meter, e.g. to measure the input water temperature and the thermistor self-heating temperature. Range constant voltage (RCV) was applied for self-heating thermistor power supply in different ranges of input water temperature. Modeling of the heat loss in the flow-meter for water was derived from heat balance equations for a self-heated thermistor in static water and in water flow conditions (static and dynamic thermistor temperature). Both temperatures (static and dynamic) were related to self-heating currents. The input water temperature was measured independently by a cold thermistor. Other parameters such as water thermal conductivity, thermistor exponential factor B and nominal thermistor resistance at room temperature were included in the thermistor heat balance equations. The logarithmic behavior of self-heating thermistors in the water flow enable modeling of heat loss as a function of static and dynamic currents related to static and dynamic thermistor temperatures. The model achieved was used in the fitting procedure of measured data of the flow-meter response.

Heat Loss Flowmeter for Water Based on Thick Film Thermistors in Power Save Regime

2021 ◽  
Vol 21 (1) ◽  
pp. 199-206
Author(s):  
Stanko O. Aleksic ◽  
Nebojsa S. Mitrovic ◽  
Miloljub D. Lukovic ◽  
Snezana G. Lukovic ◽  
Nenad T. Nikolic
Keyword(s):  
Thick Film ◽  
Heat Loss ◽  
Water Based

Sensor applications of thick-film technology

1988 ◽  
Vol 135 (4) ◽  
pp. 77 ◽  
Author(s):  
J.E. Brignell ◽  
N.M. White ◽  
A.W.J. Cranny
Keyword(s):  
Thick Film ◽  
Sensor Applications ◽  
Thick Film Technology

scholarly journals Examination of Thick-Films Using Modern Surface Analytical Techniques

1984 ◽  
Vol 11 (3) ◽  
pp. 219-223 ◽  
Author(s):  
G. Harsányi ◽  
G. Ripka
Keyword(s):  
Integrated Circuits ◽  
Thick Film ◽  
Analytical Methods ◽  
Thick Films ◽  
Analytical Techniques ◽  
Electrical Measurements ◽  
Surface Impurity ◽  
And Migration

Modern surface analytical methods/EMPA, AES, SIMS etc. were used for studying the different layers in thick-film integrated circuits. Diffusion and migration effects, surface impurity distributions and surface compositions were examined. Some of the results are presented in this paper. Electrical measurements are not discussed here; only examples of the practical use of the methods are demonstrated.

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.

Improving Stitch Bond on Hybrid Thick Film Substrate using Stand-Off Stitch Wire Bond Technique

2015 ◽  
Vol 2015 (1) ◽  
pp. 000425-000429 ◽  
Author(s):  
Richard C. Garcia
Keyword(s):  
Thick Film ◽  
Dielectric Materials ◽  
Glass Frit ◽  
Ceramic Substrate ◽  
Wire Bond ◽  
Design Requirements ◽  
The Wire ◽  
Film Substrate ◽  
Pull Tests ◽  
Associated Variables

Thick film technology is based on a paste containing glass frit that is screen printed and fused at high temperature onto various ceramic substrate materials. Softening or melting this glassy frit forms a cohesive layer, binding the conductors, resistors or dielectric materials to the ceramic. The dynamics of the printing process and inherent number of associated variables negatively impact the uniformity of the fired surface on a micro scale, which can lead to variation in the wire bonding process. Other processes associated with thick film substrate fabrication can cause problems as well. Laser trimming is used to adjust the value of printed resistors to meet design requirements. This ablation of printed resistors by high–powered pulse laser leaves a halo of debris and contamination on the ceramic substrate, which can cause wire bond lifting. In this paper, we will demonstrate a way to eliminate these problems using a bonding technique called Stand- Off Stitch bonding (SOS). This wire bond type is formed by first placing a ball bump at the second bond, or stitch, location on the thick film substrate, and then forming a normal wire that terminates on that bump. This places two ball bumps at each end of the wire, similar to a security bond. However, the ball bump is located under the stitch instead of on top. This SOS wire bond technique is compliant with the MIL-STD- 883 for a compound bond, where one bond is placed on top of another bond. With the gold bump placed on top of the gold thick film pad, the bump acts as a foundation for the stitch bond, providing a wider contact area and clean bond surface to secure a reliable stitch bond interconnect. With this change, an abrupt improvement to the resultant destruct wire pull tests can be achieved, promoting a robust, controlled process for wire bond interconnects.

Silicon strain gages bonded on stainless steel using glass frit for strain sensor applications

2014 ◽  
Vol 25 (5) ◽  
pp. 055102 ◽  
Author(s):  
Zongyang Zhang ◽  
Xingguo Cheng ◽  
Yi Leng ◽  
Gang Cao ◽  
Sheng Liu
Keyword(s):  
Stainless Steel ◽  
Strain Sensor ◽  
Glass Frit ◽  
Strain Gages ◽  
Sensor Applications
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