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This paper presents experimental data associated with the properties of thick film thermistors based on a spinel‐type semiconducting oxide/RuO2/glass system. The following parameters—sheet resistivity, thermistor (B) and thermal time (?) constants—have been measured, all as functions of different composition and construction variants. The thermistor properties are independent of configuration and are mainly determined by the semiconducting oxide particle chains. The correlation between B and ? for the compositions considered has been observed.

The purpose of this paper is to characterize electrical properties of nickel-phosphorus (Ni-P) thin-film resistors made on FR-4 laminate in a wide range of temperature (from −180 to 20°C).

The study was performed using resistors made of Ni-P foil with two different thicknesses (0.1 or 0.05 μm) and sheet resistances (100 or 250 Ω/sq), respectively. The resistance rectangular resistors had length and width from the range between 0.59 and 5.91 mm. The resistance versus temperature characteristics and their distribution as well as resistors ' durability to low-temperature thermal shocks were investigated.

The results showed almost linear temperature dependence of resistance with a negative temperature coefficient of resistance of about −95 ppm/°C for 250 Ω/sq layer and −55 ppm/°C for 100 Ω/sq layer. A very small dimensional effect was observed for sheet resistance as well as for R(T) characteristic. Thin-film resistors are also characterized by very high durability to low-temperature thermal shocks.

The results presented in this paper can be very useful for low-temperature applications of thin-film resistors made on printed circuit boards. They suggest possibility of wide applications of these components in a wide temperature range.

Thermal properties of Pt or RuO₂ thick‐film heaters made on alumina, aluminum nitride or low temperature co‐fired ceramics (LTCC) were compared in the first step of our work. Special holes to improve the heat distribution were included. Several heater layouts were analysed. The heat distribution was measured by an infrared camera, at different heating power. Second, the optimization of LTCC constructions was carried out. The simple structure of LTCC permitted the achievement of a high package density. It was possible to integrate a heating element made from special thick‐film ink as a buried film, inside a substrate. An important step in our technology was the making of the holes. A pattern of holes (achieved by punching or laser cutting) around the heating area permitted a changeable heat gradient. The quality of lamination and the structure of the buried elements were investigated with an ultrasonic microscope.

The purpose of this paper is to present a novel concentration estimation model for improving the accuracy and robustness of low-cost electronic noses (e-noses) with metal oxide semiconductor sensors in indoor air contaminant monitoring and overcome the potential sensor drift.

In the quantification model, a piecewise linearly weighted artificial neural network ensemble model (PLWE-ANN) with an embedded self-calibration module based on a threshold network is studied.

The nonlinear estimation problem of sensor array-based e-noses can be effectively transformed into a piecewise linear estimation through linear weighted neural networks ensemble activated by a threshold network.

In this paper, a number of experimental results have been presented, and it also demonstrates that the proposed model has very good accuracy and robustness in real-time indoor monitoring of formaldehyde.

A capacitor is a basic electronic passive component. Thick‐film technology allows manufacturing of capacitors covering the range of small and medium capacitances and they have been investigated in depth already. Low temperature co‐fired ceramics (LTCC) technology makes it possible to fabricate buried capacitors, which leads to increased packaging density, but such components’ properties are not well known. The purpose of this paper is to present the results of investigations on thick‐film and LTCC capacitors made in various technological variants.

Thick‐film and LTCC capacitors were made in various technological variants. Different capacitor inks, metallurgy of electrodes and component constructions were investigated. Basic electrical properties and stability were determined. An electrical equivalent circuit of such components was developed based on frequency and temperature characteristics.

Simple electrical equivalent circuits of self‐made thick‐film and LTCC micro‐capacitors were developed based on measurements in frequency and temperature domain. Good fitting accuracy was obtained. The bulk material section of model is predominant in the low‐frequency range. Interface region and serial resistance influence are revealed at higher frequency, affecting mainly dissipation factor value. Also, temperature and thermal ageing have affected strongly on that part of the model.

The paper usefully examines the electrical properties and electrical equivalent models of thick‐film and LTCC micro‐capacitors.

The International Electronic Components Show in Paris in November, 1983, provided the occasion for a very successful meeting of ISHM‐France which attracted 170 attendees. The following presentations were given:

The purpose of this paper is to study tuneable positive temperature coefficient (PTC) effect in polymer-wax-carbon composite resistors. The resistivity dependence on temperature of composite resistors made of carbon fillers dispersed in an organic matrix is known to be strongly affected by the matrix thermal expansion. High PTC effects, i.e. essentially switching from resistive to quasi-insulating behaviour, can be caused by phase changes in the matrix and the assorted volume expansion, a behaviour that has been previously shown with both simple organic waxes and semi-crystalline polymers. However, waxes become very liquid on melting, possibly resulting in carbon sedimentation, and tuneability of semi-crystalline polymers is limited.

The authors therefore study a ternary polymer-wax-conductor (ethylcellulose-octadecanol-graphite) composite resistor system, where polymer and wax fuse to a viscous liquid on heating, and re-solidify and separate by crystallisation of the wax on cooling.

It is shown that with appropriate formulation, the resulting resistors exhibit strong PTC effects, linked with the melting and crystallisation of the wax component. The behaviour somewhat depends on sample history, and notably cooling speed.

The phase equilibria and transformation kinetics of the polymer-wax system (including possible wax polymorphism), as well as the exact mechanism of the conductivity transition, remain to be investigated.

As many compatible polymer-wax systems with different melting/solidification behaviours are available, ternary polymer-wax-conductor composite PTC resistors allow a high tuneability of properties. Moreover, the high viscosity in the liquid state should largely avoid the sedimentation issues present with binary wax-conductor systems.

ISHM‐Benelux held its 1987 Autumn Conference on 29 October, at the Antwerp Crest Hotel. This one‐day meeting focused on applications of hybrid circuit technology in various fields of electronic and related industries.

Eighty‐five participants attended the 4th ISHM Display meeting at the Jaarbeurs Congress Centre in Utrecht on 16 October, 1986. The programme of the day started with the annual general membership meeting of the Benelux Chapter. The chairman, Mr T. Kwikkers, gave a short review of the state of affairs of ISHM‐Benelux and of the activities of the last year. He mentioned the temporary enlargement of the executive committee to give a new generation a chance to gain experience in the ISHM organisation and to take up some new activities. In order to raise publicity for ISHM and Hybrid Circuits a new brochure has been designed and a set of material for demonstration purposes was collected. With the material every member of the chapter can easily set up a presentation for schools or customers. This year ISHM‐Benelux has grown from 85 to 100 members and enjoys a healthy financial situation. Next year again emphasis will be put on public relations. Professor R. Govaerts signified that he was no longer available for a position in the executive committee. As Prof. Govaerts has been very active and stimulating for the ISHM‐Benelux Chapter from its foundation in 1976 up to now, the general membership meeting decided to appoint him as (the first) honorary member of this chapter. Except for Professor Govaerts, the sitting executive committee, consisting of 15 members, was re‐elected for another year. After the European conferences in Bournemouth and Hamburg the ISHM‐Benelux chapter is asked to organise the 1991 Conference. The executive committee is already looking out for candidates for a function in the organising committee, which must be formed in the coming year.

This paper presents a computer model which describes the influence of microcracks on the temperature dependence of resistance in thick film resistors. The tunnelling barrier model for a single particle‐barrier‐particle ‘unit cell’, proposed by Seager and Pike, is assumed. The model presented is based on an analysis of the critical percolation path that forms in the sample. It is shown that the growth in density of the microcracks induces a shift of the minimum resistance to higher temperatures, and that the value of this minimum decreases. The theoretical temperature dependences of resistance are compared with experimental data, obtained in the temperature range 295K–425K, for thick film resistors made using Du Pont 1421 and 1431 Birox resistor pastes.