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The purpose of this paper is to investigate the behavior of embedded passives under changing temperature conditions. Influence of different temperature changes on the basic properties of embedded passives was analyzed. The main reason for these investigations was to determine functionality of passives for space application.

The investigations were based on the thin-film resistors made of Ni-P alloy, thick-film resistors made of carbon or carbon-silver inks, embedded capacitors made of FaradFlex materials and embedded inductor made in various configurations. Prepared samples were examined under the influence of a constant elevated temperature (100, 130 or 160°C) in a long period of time (minimum of 30 h), thermal cycles (from −40 to +85°C) or thermal shocks (from −40 to +105°C or from −40 to +125°C).

The achieved results revealed that resistance drift became bigger when the samples were treated at a higher constant temperature. At the same time, no significant difference in change in electrical properties for 50 and 100 Ω resistors was noticed. For all the tests, resistance change was below 2 per cent regardless of a value of the tested resistors. Conducted thermal shock studies indicate that thin-film resistors, coils and some thick-film resistors are characterized by minor variations in basic parameters. Some of the inks may show considerable resistance variations with temperature changes. Significant changes were also exhibited by embedded capacitors.

The knowledge about the behavior of the operating parameters of embedded components considering environmental conditions allow for development of more complex systems with integrated printed circuit boards.

This paper aims to focus on the fabrication and characterization of mixed thin-/thick-film thermoelectric microgenerators, based on magnetron sputtered constantan (copper–nickel alloy) and screen-printed silver. To improve the adhesion of the constantan layer to the applied substrates, the additional chromium sublayer was used. The aim of the study was to investigate the influence of chromium sublayer on the electrical and thermoelectric properties of such hybrid microgenerators.

Fabrication of such structures consisted of several steps – magnetron sputtering of the chromium and then constantan layer, exposing the first arms of thermocouples, applying the second arms by screen-printing technology and firing the prepared structures in a belt furnace. The structures were made both on Al₂O₃ (alumina) and low temperature co-fired ceramics (LTCC) substrates.

To the best of the authors’ knowledge, for the first time, laser ablation process was applied to fabricate the first arms of thermocouples from a layer of constantan only or constantan with a chromium sublayer. Geometric measurements have shown that the mapping of mask pattern by laser ablation technique is very accurate.

The determined Seebeck coefficient of the realized structures was about 40.4 µV/K. After firing the exemplary structures at 850°C peak temperature, Seebeck coefficient is increased to an average value of 51 µV/K.

The paper focuses on design, fabrication and characterization of electromagnetic microgenerators with integrated rectifying circuits to convert AC output signal to DC one. The work includes research on simulation of voltage-rectifying circuits, including charge pump, realization of the experimental printed circuit board (PCB) with selected electronic circuits and the execution of the final structure with integrated rectifying circuit. Measurements were performed on these circuits.

Electromagnetic microgenerators include multipole permanent magnets secured on rotor three-phase brushless direct current (BLDC) motor and planar multilayer multiple coils. These were fabricated using low temperature co-fired ceramics (LTCC) technology. In our experiment, six rectifying circuits were simulated and tested with a structure consisting of eight layers of coils and with an outer diameter of 50 mm fabricated earlier.

The microgenerator with Graetz bridge generates higher output power than the modified charge pump at the same rotary speed. However, it is less stable for the distance change between the structure and the magnets than the modified charge pump, which has more constant output power in a wider range of load resistance.

The presented electronic rectifying circuits are novel for LTCC-based electromagnetic microgenerator application. The structure with integrated rectifying circuits allows generation of electrical output power larger than 100 mW at the rotor speed of about 8,000 rpm.

The paper aims to verify the influence of mechanical factors (longitudinal elongation at constant stretching velocity, constant elongation strain and cyclic compressive and tensile stresses) on the electrical properties of thin-film and polymer thick-film resistors on flexible substrates.

Kapton foil was used as a substrate for all test samples. Designed resistive structures were made with the aid of two polymer thick-film resistive inks or OhmegaPly Ni-P resistive foil. Two different topologies – the horseshoe and triangular – were used. These topologies should have the opposite stability parameters.

Almost all presented data confirm the influence of the topology of resistors on stability of their electrical properties. The resistive materials applied for test structures also affect the stability under various mechanical exposures.

In general, the largest changes were caused by longitudinal elongation at constant stretching velocity, whereas other tests caused smaller changes of electrical properties. The measurements confirm the influence of topology on stability of electric properties.

The purpose of this paper is to investigate the basic functional parameters of passive embedded components in printed circuit boards (PCBs) under environmental exposures such as thermal-humidity and thermal exposure.

The investigations were based on the thin-film resistors made of NiP alloy, thick-film resistors made of carbon or carbon–silver inks, embedded capacitors made of FaradFlex materials and embedded inductor made in various configurations. The capacitors and thin- and thick-film resistors were tested in the climatic chamber in conditions of thermal-humidity exposure at 85°C and 85 per cent RH for 500 h. The embedded inductors were tested in two different environmental conditions: thermal-humidity exposure at 60°C and 95 per cent RH, and thermal exposure at 150°C and additionally at the temperature in the range of +25°C to +150°C.

Studies show that in the case of embedded capacitors, the changes caused by exposure to thermal-humidity are durable and lead to the capacity increase. The embedded thin-film resistors behave in the same manner, whereas the thick-film resistors were the least resistant to the conditions of exposure. Most of the polymer thick-film resistors have been damaged. The changes of coils' properties during aging are small, and what is most important is that, after some time of exposure, their parameters stabilize at a particular level. The changes resulting from the increase in temperature are typically related to the change of material resistance (Cu) of which coils are made, and as such, they cannot be avoided but they can be predicted.

The realized studies allowed determination of the properties of the embedded passive elements with respect to specific environmental exposures. The studies show that embedded resistors can be used interchangeably with chip passive elements. It allows saving the area on the surface of PCB, occupied by these passive elements, for assembly of active elements integrated circuits (ICs) and thus enabling the miniaturization of electronic devices.

The knowledge about the behavior of the operating parameters of embedded components, considering the environmental conditions, allows for development of more complex systems with integrated PCBs.

This paper aims to present systematic studies of a wide spectrum of geometrical and electrical properties of thick‐film and LTCC microresistors (with designed dimensions between 50 × 50 μm² and 800 × 200 μm²).

The geometrical parameters (average length, width and thickness, relations between designed and real dimensions, distribution of planar dimensions) are correlated with basic electrical properties of resistors (sheet resistance and its distribution, hot temperature coefficient of resistance and its distribution distribution) as well as long term thermal stability and durability of microresistors to short electrical pulses.

Fodel process gives better resolution than standard screen‐printing and leads to smaller dimensions than designed, smaller absolute error and better uniformity of planar sizes. Microresistors made in full Fodel process show much weaker dimensional effect and exhibit noticeably smaller distribution of basic electrical properties.

Presents systematic studies of a wide spectrum of geometrical and electrical properties of thick‐film and LTCC microresistors.

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.

The paper aims to get the knowledge about electrical properties, including noise, of modern polymer thick-film resistors (TFRs) in a wide range of temperature values, i.e. from 77 K up to room temperature. The sample resistors have been made of different combinations of resistive compositions, either ED7100 or MINICO (M2013, M2010), and conducting pastes (for contacts) Cu- or Au-based, deposited on FR-4 laminate.

The paper opted for an experimental study using either current noise index measurement in room temperature for large batch of samples or noise spectra measurement in temperature range 77-300 K for selected samples. Obtained noise maps, i.e. plots of power spectral density of voltage fluctuations vs frequency and temperature, have been used for evaluation of noise describing parameters like material noise intensity C and figure of merit K, for TFRs made of different combinations of resistive/conductive materials. Comparison of the parameters gives the information about the quality of the technology and matching the conductive/resistive materials.

Experiments confirmed that the main noise component is 1/f resistance noise. However, low-frequency noise spectroscopy revealed that also noise components of Lorentzian shape, associated with thermally activated noise sources exist. Their activation energies have been found to be of a few tenths of eV.

The noise intensity of polymer TFRs depends on technology process and/or contacts materials. The use of Au contacts leads to better noise properties of the resistors. The results of the studies might be helpful for further improvement of thick-film technology, especially for manufacturing low-noise, stable and reliable TFRs.

The paper includes indications for the materials selection for thick-film technology to manufacture low-noise, reliable and stable TFRs.

Experimental studies of electrical properties of polymer TFRs by means of noise spectra measurements in wide range of temperature is rare. They give fundamental knowledge about noise sources in the modern passive electronic components as well as practical indications of selection material for thick-film technology, to obtain high performance components and get technological advantage.

This paper presents possibility of laser application for fabrication of 3D elements and structures. The Aurel NAVS‐30 Laser Trimming and Cutting System with special software was used. It was applied successfully for fabrication of vias (minimum diameter – 50 μm) in fired and unfired LTCC ceramics and channels with width between 100 μm and 5 mm. The achievements and problems are presented and discussed. The influence of lamination process on quality of vias and channels as well as the problems connected with interaction of laser beam with ceramic tapes are shown. Three‐dimensional resistors and microfluidic system were successfully designed and fabricated based on our investigations. Chosen electrical and thermal parameters of constructed devices are shown, too.

The paper aims to investigate on the mechanical properties of surface-mount device (SMD) interconnections made on flexible and rigid substrates.

The durability of joints to shear strength was measured with tensile machine. Investigations were carried out for 0402- and 0603-sized ceramic passives and integrated circuits in SOIC-8, TSSOP-8, XSON3 and XSON6 packages. Three types of flexible substrates (Kapton, Mylar and Pyralux) and two types of rigid substrates (LTCC and alumina) were used. SMD components were mounted with SAC solder or electrically conductive adhesive. Contact pads were made of Ag-based polymer paste on flexible substrates and PdAg-based cermet paste on ceramics. The shear strength was measured for as-made and long-term thermally aged test structures. The average durability and standard deviation were compared for different combination of materials. Moreover, mechanical properties of interconnections made of polymer thick-film pastes or electrically/thermally conductive adhesives between ceramic chips and flexible/ceramic substrates were investigated.

The mechanical properties of joints strongly depend on configuration of applied materials. Some of them exhibit high durability to shear strength, while other should not be recommended due to very weak connections. Additionally, long-term thermal ageing showed that exploitation of such connections at elevated temperature in some cases might increase their strength. However, for some materials, it leads to accelerated degradation of joints.

This paper provides practical information about SMD interconnections made with standard materials (lead-free solder, electrically/thermally conductive adhesives) and proposed non-standard procedures, e.g. assembling of ceramic chips with low temperature cermet or polymer thick-film conductive pastes.