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Interactions between stainless steel and silver and gold based thick film conductors and YBa2Cu3O7 thick film superconductors were studied by SEM and EDX. The stainless steel reacted with the superconducting layer, forming a Ba‐Fe‐O compound on the interface, while BaO‐depleted YBa2Cu3O7 compound transformed into insulating Y2BaCuO5 compound. When YBa2Cu3O7 is fired on a gold thick film conductor, a thin layer of Y2BaCuO5 compound forms between the conductor and the superconducting film. In the case of a thin Ag conductor, BaO diffused through the silver film and reacted with alumina ceramic to the depth of a few μm. When a thicker silver layer (40–50 μm) was used, diffusion did not occur.

The aim of this paper is to investigate permittivity of nano structured Ni_0.7‐xCo_xZn_0.3Fe₂O₄ thick films at microwave frequencies.

Nanosized Ni_0.7‐xCo_xZn_0.3Fe₂O₄ ferrites with x=0, 0.04, 0.08 and 0.12 were prepared by sucrose precursor technique using the constituent metal nitrates. Thick films of the ferrites were fabricated on alumina substrates by screen‐printing technique. Microwave dielectric constant (ε′) and the loss factor (ε″) for the thick films were measured by VSWR slotted section method in the 8‐18 GHz range of frequencies. Microwave attenuation properties were studied using a waveguide reflectometer set up.

Both the ε′ and ε″ were found to vary with frequency and composition x. It is observed that, value of ε′ increases with increase in x, due to the increase in bulk density and reduction in porosity of the material, that resulted due to the substitution of cobalt in Ni‐Zn ferrite. The microwave transmission loss offered by the thick films was found to increase with the increase in cobalt concentration x. Within the band width of 4 GHz (from 12‐16 GHz), all the films except that with x=0.04 offered the reflection loss of less than 3 dB.

The dielectric constant of Ni_0.7‐xCo_xZn_0.3Fe₂O₄ thick films have been reported for the first time. These thick films provide scope for cost effective planar ferrite devices.

The microwave properties of microstripline at S‐band and X‐band and ?/2 rejection filter with midband rejection at 3 GHz fabricated by thick film technology are studied. The effect of an overcoat of Ag thin film of thickness 2 µm deposited by ion plating and electroless plating on Ag and Pd‐Ag thick film circuits is reported. There is a drastic improvement in the performance of the thick film circuits after overcoating. This is attributed to the superior edge definition whereby losses are reduced. As the edge is smoother, especially at the coupling area of the filter, there is tighter coupling, thus increasing the Q of the filter. The overcoat may also reduce the large open areas of the thick film, giving a smoother upper surface finish. This type of metallic overcoat, i.e., hybrid of thick and thin film, may reduce the need for costly and time‐consuming functional trimming and expensive thick film materials.

This paper reports the behaviour of a parallel coupled band pass microstrip filter due to an Al₂O₃ thin film‐thick film overlay and the effect of the moisture ambient on the properties of the overlaid microstrip filter. The thickness of the initial thin‐film overlay affects the behaviour of the filter after thick‐film overlay. Moisture has the effect of lowering the transmittance drastically and shifting the pass band to the lower frequency end. The filter loses its band pass characteristics after a few moisture‐heat cycles, indicating irreversible change taking place in the overlay material. It is felt that the ageing aspects of the overlay material should be taken into account when using dielectric overlays for circuit protection and cross‐over insulation purposes.

The purpose of the paper is to show up the current possibilities by combination of classic thick-film technology with advanced processing. Thick-film hybrid ceramic substrates have been a base for highly reliable devices for space, aerospace, medical and industrial applications since many years. The combination of classic thick-film printing with advanced technologies for fine line structuring provides substrates best suited for packaging solutions with challenging requirements, such as temperature stability and extended product lifetime. Combined with state of the art assembly technologies, thick-film substrates are used in highly demanding industries.

In recent years, several technologies for fine line structuring have been introduced, e.g. fine line printing, photo imaging, etching, laser structuring for local chip fan-out or fine line structuring on single layers. For further miniaturization of thick-film multilayers circuits, after solving the fine line resolution, the reduction of electrical connection of conductive layers through printed insulation/dielectric layer (via) diameters to connect the layers should be addressed.

The focus of this paper is to show the results of combining fine line structuring with laser microvias and to compare laser drilling in thick-films with different established via forming technologies.

The reduction of via size to 60 µm – smaller than 50% compared to using state-of-the-art printing technologies enables a solution for significant relaxation of current design possibilities.

Thick film thermistors based on the thermistor powder of the sintered ceramic thermistor, prepared from oxides of nickel, cobalt and manganese, were fabricated and studied. The ingredient compositions, including the composition proportions, influenced the properties of thick film thermistors. The effects of the compositions of the sintered ceramic thermistors, the amounts of additives used and the compositions of the glass binders on the properties of the thick film thermistors were also studied.

The successful use of piezoceramic thick films in sensors and actuators requires a thorough understanding of their electrical and electromechanical characteristics. Since these characteristics depend not only on the material's composition but also on its compatibility with various substrates and a number of processing parameters, accurate measurements of the material's parameters are essential. Here, the aim of this paper is to present a procedure for characterising lead‐zirconate‐titanate (PZT) thick films on pre‐fired low‐temperature co‐fired ceramic (LTCC) substrates performed in order to determine the material parameters for numerical modelling.

Owing to the lack of standard procedures for measuring the elastic and piezoelectric properties of the films, the compliance parameters were evaluated from the results of nano‐indentation tests, and a substrate‐flexure method was used to evaluate the transverse piezoelectric coefficients.

The validation of the material model and the finite‐element (FE) analysis of the demonstrator sensor/actuator structures are shown to be in agreement with the FE model, even if not an exact fit.

This paper focuses on a characterisation of PZT thick films screen‐printed on pre‐fired LTCC substrates.

This paper aims to study the structural, electrical and microwave properties of (Sr_0.6Ca_0.4) (Co_yMn_1−y) O₃ (0.2 ≤ y ≤ 1.0) thick-film ceramics.

The thick films of (Sr_0.6Ca_0.4) (Co_yMn_1−y) O₃ (0.2 ≤ y ≤ 1.0) on the alumina substrate have been delineated using screen printing technique. The structural analysis was carried out using an X-ray diffraction method and scanning electron microscopy. The direct current (DC) electrical resistivity is measured using a two-probe method. Microwave absorption was studied in the 8-18 GHz frequency range by using the Waveguide Reflectometer Method. The permittivity and permeability in the 8-18 GHz frequency range were measured by using Voltage Standing Wave Ratio slotted section method.

The thick films have orthorhombic perovskite structure with dominant (020) plane. By using first-principle calculation method, theoretical and experimental lattice parameter and cell volume of (Sr_0.6Ca_0.4) (Co_yMn_1−y) O₃ are matched with each other. The cobalt content changes the morphology from plates to needles. The DC electrical resistivity increases with increase in Co content and decreases with increase in temperature. (Sr_0.6Ca_0.4) (Co_yMn_1−y) O₃ thick film shows 75 per cent microwave absorption both in the X band and Ku band. The microwave permittivity and permeability decreases with increase in frequency and Co content.

Structural, electrical and microwave properties of (Sr_0.6Ca_0.4) (Co_yMn_1−y) O₃ (0.2 ≤ y ≤ 1.0). Thick film ceramics on alumina substrate is reported for the first time.

The paper presents the application of two advanced thick‐film techniques: etching of fired thick‐films and photoimaging of photosensitive thick‐films for fabrication bandpass microwave filters operating in the frequency range from 6 to 14 GHz. Modified screen printing through ultra‐thin calendered screens is used for comparative goals. Advanced techniques are combined with novel thick‐film conductors including photosensitive pastes and etchable pastes.

The purpose of this paper is to investigate and report the impact of glass frit variation in silver thick film pastes used as surface conductors in low temperature co‐fired ceramics technology (LTCC), especially on the properties such as warpage of LTCC associated with conductors, microstructure of the fired thick films, sheet resistance and adhesion on LTCC.

Silver thick film paste compositions were formulated by changing the silver glass frit ratio. The compatibility of these formulated paste compositions with LTCC (DP 951AX) substrate were evaluated. The properties such as microstructure developments, the change in sheet resistance, warpage of LTCC substrate with respect to glass frit ratio of the developed silver films on LTCC were evaluated.

The results reveal that the glass frit percentage used in paste formulation is equally responsible for the disturbance in the properties such as microstructure, warping and electrical properties of the fired thick films on LTCC. It was observed that the paste composition, in particular sample SP10B containing the highest glass frit percentage, is compatible with the LTCC tape under processing conditions. The sheet resistance value in the range of 5 mΩ/□ and the fired films showed very good adhesion (3.95 N), irrespective of the glass frit composition.

The paper provides useful evaluations of properties such as microstructure developments, changes in sheet resistance and warpage of LTCC substrate with respect to glass frit ratio of the developed silver pastes on LTCC.