Electrical characterization of thick film materials

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000079-000084
Author(s):  
L. Rebenklau ◽  
P. Gierth ◽  
H. Grießmann

The thick-film technology is one of the fundamental technologies for the production of circuit carriers for electronic modules. It is mainly used in areas with harsh environmental conditions, such as sensor or automotive applications. Basis of the thick film technology are glass-based pastes, which are screen printed on ceramic substrates and fired in a high temperature process at (500…1000) ° C. Such thick film pastes are commercially available from various suppliers as elements of paste systems, which mainly include compatible isolation, resistance and conductive pastes. There are a number of requirements according the fired thick film characteristics, such as high breakdown voltage of isolation thick films or low noise performances of resistance thick films. However, the most requirements are concentrating on conductor thick films. They should guarantee excellent properties in terms of assembling (soldering, bonding) which are focused in a many publications. Simultaneously, they should also offer very good electrical characteristics that have not been completely investigated until today. At Fraunhofer IKTS different measurement methods are developed and adapted to characterize the electrical performance of thick film structures. Already well known is the short term overload (STOL) measurement of thick film resistances, which determining the maximum power dissipation of the thick film structure. The basic concept of this measurement is adapted on conductive thick film structures like conductive tracks or vias. The investigations show correlations between geometrical thick film properties and the resulting thermal characteristics of the thick film structure. Results can be used to improve screen-printing layouts in terms of cost reduction (paste consumption) and thermal management (track width, via diameter), but can also help to improve paste compositions itself. The paper will give an overview of the used electrical measurement methods and present exemplary results.

1977 ◽  
Vol 4 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Per Chr. Malmin

During the last few years, the use of hybrid integrated circuits in microwave radio links has increased significantly. This paper reports on a range of microwave hybrid circuits now in production at our plant. These include transistor high power amplifiers, low noise mixers and various other circuits. The hybrid technology has proven to be cost competitive with the more conventional waveguide and coaxial technologies, and gives quite a few other advantages as well. Among these, the standardization of packages and modules is discussed in some detail. The trend is now to use the hybrid technology in VHF circuits as well. This opens up the possibility of integrating related functions in one package. The production cost in this case must be related to printed circuit boards, and it remains to be seen if there is anything to gain in this respect. However the reduction of the size of modules and the time for circuit alignment will certainly give an improvement in the overall system cost. In order to reduce the cost of microwave hybrid circuits, thick film technology is currently being investigated for use up to 15 GHz. There is probably no specific upper frequency for thick film circuits, but the possibility of using conventional thick film technology depends on the actual circuits under consideration. Preliminary results of this work are reported, together with a cost comparison between thick film and thin film microwave hybrid circuits.


1998 ◽  
Vol 13 (7) ◽  
pp. 1865-1874 ◽  
Author(s):  
Simona Immovilli ◽  
Bruno Morten ◽  
Maria Prudenziati ◽  
Alessandro Gualtieri ◽  
Massimo Bersani

We investigated the interactions between screen printed and fired layers of Bi2O3 and ceramic substrates of alumina and beryllia. It was found that the reaction products are invariably crystalline in nature. Several transitions of Bi2O3 in its polymorphic phases were found to occur on BeO substrates, while newly formed compounds have been observed to grow on alumina substrates, i.e., Al4Bi2O9 on 99.9% Al2O3 and Bi12SiO20 on 96% Al2O3. Bismuth deeply penetrates in the ceramic interstices in all the cases. Until Bi2O3 is not completely reacted, this penetration is diffusion limited (penetration depth , where td is the reaction time) with values of the activation energy ranging from 3.7 ± 0.6 eV (BeO substrate) to 1.4 ± 0.06 eV (96% Al2O3 substrate). It is shown that these processes are notably different to those occurring in PbO/ceramic systems; moreover, they imply different adhesion phenomena of thick films on different substrates.


2015 ◽  
Vol 27 (3) ◽  
pp. 115-119 ◽  
Author(s):  
Adam Witold Stadler ◽  
Andrzej Kolek ◽  
Krzysztof Mleczko ◽  
Zbigniew Zawiślak ◽  
Andrzej Dziedzic ◽  
...  

Purpose – 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. Design/methodology/approach – 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. Findings – 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. Research limitations/implications – 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. Practical implications – The paper includes indications for the materials selection for thick-film technology to manufacture low-noise, reliable and stable TFRs. Originality/value – 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.


1976 ◽  
Vol 22 (11-12) ◽  
pp. 791
Author(s):  
R. Naylor

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 59
Author(s):  
Deepak Rajaram Patil ◽  
Venkateswarlu Annapureddy ◽  
J. Kaarthik ◽  
Atul Thakre ◽  
Jun Akedo ◽  
...  

Conventional thin-film processing techniques remain inadequate for obtaining superior dense ceramic thick films. The incompatibility of ceramic films prepared via other methods, such as screen printing, spin coating, and sputtering, is a major obstacle in the fabrication of thick film-based ceramic electronic components. The granule spray in vacuum (GSV) processes and aerosol deposition (AD) are important coating approaches for forming dense ceramic thick films featuring nanoscale crystallite structures at room temperature, which offer excellent material properties and facilitate cost-effective production. AD ceramic coatings require the acceleration of solid-state submicron ceramic particles via gas streams with a velocity of a few hundred meters per second, which are then wedged onto a substrate. This process is economical and particularly useful for the fabrication of piezoelectric thick film-based microactuators, energy harvesters, sensors, and optoelectronic devices. More recently, the GSV technique was improved to achieve more uniform and homogeneous film deposition after AD. This review article presents a detailed overview of the AD and GSV processes for piezoelectric thick films in terms of recent scientific and technological applications.


1988 ◽  
Vol 135 (4) ◽  
pp. 77 ◽  
Author(s):  
J.E. Brignell ◽  
N.M. White ◽  
A.W.J. Cranny

1984 ◽  
Vol 11 (3) ◽  
pp. 219-223 ◽  
Author(s):  
G. Harsányi ◽  
G. Ripka

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.


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