bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase-contrast versus off-axis illumination: is a more complex microscope always more powerful?
Authors: Hostounský Zdeněk , Pelc Radek
Published: June 2007

In this article, a practical demonstration suitable for any biology college classroom is presented. With the examples of a complex biological specimen (slug's radula) and a simple reference specimen (electron microscopical grid imprint in gelatin), both of which can be easily prepared, the capabilities of two imaging modes commonly used in optical microscopy are demonstrated. The results obtained under phase contrast (a rather sophisticated method, 1953 Nobel Prize to Zernike) and off-axis illumination (a very simple method) are compared. The off-axis illumination setup is capable of delivering noticeably better microscopic images of these two particular specimens, yet it can be easily assembled in a laboratory classroom. The outcome of such a demonstration is expected to be the realization on the part of the students that one needs to carefully choose the apparatus to address a given biological problem, with the “bottom line” being that a more complex one may not necessarily yield better results. An attempt to explain this “paradox” is presented, in the particular case presented here, partly from the physiology of vision perspective (the shape-from-shading problem). The overall aim of the present article is to induce in students critical thinking about the capabilities of a laboratory equipment in general and about data interpretation.
Expanding course goals beyond disciplinary boundaries: physiology education in an undergraduate course on psychoactive drugs
Authors: Near Joseph A. , Martin Bruce J.
Published: June 2007

The topic of psychoactive drugs is one of inherent interest to college students. We used this insight to design and implement a multidisciplinary undergraduate course with psychoactive drugs as the central theme. The Medical Science of Psychoactive Drugs examines the biological mechanisms underlying all major effects of psychoactive drugs, including the effects on the brain and other organs and tissues. Physiological principles, molecular mechanisms, and genetic factors involved in drug-induced therapeutic and adverse effects are emphasized. The course is open to undergraduate students at all levels and carries no prerequisites, and enrollment is limited to ∼50 students. Major teaching modes include lecture, short homework papers on topics related to the previous class meeting, small-group discussions at several points during each class, and whole class discussions. Because of the diversity of students' knowledge of basic science, we employ a variety of methods designed to help students grasp the necessary scientific concepts. Our methods are intended to be inquiry based and highly interactive. Our goals are 1) to foster the development of an organized knowledge base about psychoactive drugs that will have practical applicability in the daily lives of the students; 2) to promote the rational application of this knowledge in thinking about current medical, social, legal, and ethical issues involving psychoactive drugs; and 3) to cultivate science literacy, critical thinking, and communication skills among students.
Gender differences in learning style preferences among undergraduate physiology students
Authors: Wehrwein Erica A. , Lujan Heidi L. , DiCarlo Stephen E.
Published: June 2007

Students have individual learning style preferences including visual (V; learning from graphs, charts, and flow diagrams), auditory (A; learning from speech), read-write (R; learning from reading and writing), and kinesthetic (K; learning from touch, hearing, smell, taste, and sight). These preferences can be assessed using the VARK questionnaire. We administered the VARK questionnaire to undergraduate physiology majors enrolled in a capstone physiology laboratory at Michigan State University; 48 of the 86 students (55.8%) who returned the completed questionnaire voluntarily offered gender information. The responses were tallied and assessed for gender difference in learning style preference; 54.2% of females and only 12.5% of males preferred a single mode of information presentation. Among the female students, 4.2% of the students preferred V, 0% of the students preferred A, 16.7% of the students preferred printed words (R), and 33.3% of the students preferred using all their senses (K). In contrast, male students were evenly distributed in preference, with 4.2% of the students preferring A, R, or K, respectively, while 0% of the students preferred V. Furthermore, 45.8% of female and 87.5% of male respondents preferred multiple modes [female: 2 modes (12.5%), 3 modes (12.5%), and 4 modes (20.8%); males: 2 modes (16.7%), 3 modes (12.5%), and 4 modes (58.3%)] of presentation. In summary, a majority of male students preferred multimodal instruction, specifically, four modes (VARK), whereas a majority of female students preferred single-mode instruction with a preference toward K. Thus, male and female students have significantly different learning styles. It is the responsibility of the instructor to address this diversity of learning styles and develop appropriate learning approaches.
Helping students make sense of physiological mechanisms: the “view from the inside”
Authors: Modell Harold I.
Published: June 2007

Students often view physiological mechanisms in descriptive terms from a perspective that does not help them recognize causal relationships. The “view from the inside” is a technique that helps students focus on causal relationships from the “viewpoint” of a reporter standing inside of the system. Qualitative data indicate that the technique helps students to recognize the applicability of general models in physiology, make sense of difficult physiological mechanisms, and develop learning strategies that they apply to other disciplines. The technique is also useful in helping students recognize conceptual or reasoning difficulties in their mental models (misconceptions).
Information literacy in an inquiry course for first-year science undergraduates: a simplified 3C approach
Authors: Rangachari P. K. , Rangachari Usha
Published: June 2007

In this article, we describe a simplified approach to teach students to assess information obtained from diverse sources. Three broad categories (credibility, content, and currency; 3C) were used to evaluate information from textbooks, monographs, popular magazines, scholarly journals, and the World Wide Web. This 3C approach used in an inquiry course for freshmen in an undergraduate science program can be readily transferred to other settings.
Fishing for an ECG: a student-directed electrocardiographic laboratory using rainbow trout
Authors: Cotter Paul A. , Rodnick Kenneth J.
Published: June 2007

Cardiac physiology is emphasized in many undergraduate physiology courses, but few nonmammalian vertebrate model systems exist that 1) can be studied fairly noninvasively, 2) are well suited for controlled experimentation, and 3) emphasize principles characteristic of the vertebrate heart. We have developed an inquiry-based undergraduate/graduate-level laboratory in cardiac physiology and electrocardiography using rainbow trout ( Oncorhynchus mykiss Walbaum) and the BioPac MP30 data-acquisition system (other fish species and/or electrocardiographic recording devices can be substituted). This laboratory facilitates intensive study of vertebrate electrocardiograms (ECGs) under a variety of environmental and physiological perturbations and is ideal for use in multisession, inquiry-based laboratory projects in animal physiology. Furthermore, students gain valuable experience in scientific inquiry, study design, following and/or developing scientific protocols, and animal care. This laboratory requires the ability to keep captive fish of at least 100 g and equipment to record ECGs. Departments meeting these requirements can adopt this technique at modest expense. Student enthusiasm and feedback were positive, and several students commented that the nonlethal methods used added to the laboratory's perceived value.
Using explicit teaching to improve how bioscience students write to the lay public
Authors: Moni Roger W. , Hryciw Deanne H. , Poronnik Philip , Moni Karen B.
Published: June 2007

The media role model was recently developed to frame how science faculty members can teach their students to write more effectively to lay audiences ( 14 ). An Opinion Editorial (Op-Ed) was introduced as a novel assignment for final-year physiology and pharmacology undergraduates. This second phase of this study, reported here, demonstrated the efficacy of explicit teaching of the Op-Ed, using a one-shot, pre-/posttest research design. Baseline writing skills of students were determined from a communication assignment. Students were then explicitly taught how to write an Op-Ed and subsequently wrote an Op-Ed based on a recent, relevant scientific article. Most students achieved higher grades for their Op-Ed following explicit teaching [mean (SD) = 84.4% (9.1%), n = 216] compared with their communication assignment [mean (SD) = 74.7% (11.9%), n = 218]. Improvement in student writing was also evident by an increase in text readability, which mirrored the features of Op-Eds written by professional journalists. A survey of students ( n = 142) indicated that most believed that the assignments were valuable and that their ability to write to a lay audience had improved. Members of the lay public were then surveyed for their opinions on student writing. Two assignments were selected from one student whose grades had improved after explicit teaching. Respondents ( n = 78) indicated that the Op-Ed was easier to read than the communication assignment. Thus, explicit teaching of the Op-Ed improved the ability of students to write to members of the lay public.
Endocannabinoids acting at CB1receptors mediate the cardiac contractile dysfunction in vivo in cirrhotic rats
Authors: Bátkai Sándor , Mukhopadhyay Partha , Harvey-White Judith , Kechrid Raouf , Pacher Pál , Kunos George
Published: June 2007

Advanced liver cirrhosis is associated with hyperdynamic circulation consisting of systemic hypotension, decreased peripheral resistance, and cardiac dysfunction, termed cirrhotic cardiomyopathy. Previous studies have revealed the role of endocannabinoids and vascular CB1receptors in the development of generalized hypotension and mesenteric vasodilation in animal models of liver cirrhosis, and CB1receptors have also been implicated in the decreased β-adrenergic responsiveness of isolated heart tissue from cirrhotic rats. Here we document the cardiac contractile dysfunction in vivo in liver cirrhosis and explore the role of the endocannabinoid system in its development. Rats with CCl4-induced cirrhosis developed decreased cardiac contractility, as documented through the use of the Millar pressure-volume microcatheter system, low blood pressure, and tachycardia. Bolus intravenous injection of the CB1antagonist AM251 (3 mg/kg) acutely increased mean blood pressure, as well as both load-dependent and -independent indexes of systolic function, whereas no such changes were elicited by AM251 in control rats. Furthermore, tissue levels of the endocannabinoid anandamide increased 2.7-fold in the heart of cirrhotic compared with control rats, without any change in 2-arachidonoylglycerol levels, whereas, in the cirrhotic liver, both 2-arachidonoylglycerol (6-fold) and anandamide (3.5-fold) were markedly increased. CB1-receptor expression in the heart was unaffected by cirrhosis, as verified by Western blotting. Activation of cardiac CB1receptors by endogenous anandamide contributes to the reduced cardiac contractility in liver cirrhosis, and CB1-receptor antagonists may be used to improve contractile function in cirrhotic cardiomyopathy and, possibly, in other forms of heart failure.
Membrane type 1 matrix metalloproteinase is necessary for distal airway epithelial repair and keratinocyte growth factor receptor expression after acute injury
Authors: Atkinson Jeffrey J. , Toennies Holly M. , Holmbeck Kenn , Senior Robert M.
Published: June 2007

Membrane type 1 matrix metalloproteinase (MT1-MMP) is a protease produced by airway epithelial cells in various diseases. Since other MMPs are involved in bronchial epithelial repair, we investigated the role of MT1-MMP in naphthalene-induced small airway injury and repair in wild-type (WT) and MT1-MMP-knockout (KO) mice. The degree of injury was similar in both strains, but the MT1-MMP KO mice were unable to reconstitute a normal, fully differentiated airway epithelium 28 days after injury. MT1-MMP was required for the proliferative response in distal airway epithelial cells, resulting in decreased cell density and airway epithelial cell differentiation in MT1-MMP KO mice. Surprisingly, EGF-mediated signaling was unaltered in MT1-MMP KO mice and therefore unrelated to the proliferative response. However, keratinocyte growth factor receptor (KGFR) expression was significantly upregulated before the proliferative response and markedly less evident in the distal airway epithelium of MT1-MMP KO mice. These results indicate MT1-MMP is involved in KGFR expression and epithelial cell proliferation after acute airway injury.
Future Development of Electronic Components
Authors: Van Vessem J. C.
Published: June 2007

The rapid progress of semiconductor products in the electronic industry over the past two decades in the group of
active components has not been matched by an equal progress of the passive components. Integration has blurred
the traditional boundary between components and circuits. With integration penetrating deeper and deeper into
electronic circuitry the connecting methods of the IC with the rest of the system becomes a cost and quality
determining factor of prime importance. It is stressed that connecting methods of the other, passive components
have to be compatible with the connecting method of the IC.
High Voltage Ceramic Capacitors
Authors: Nicker D. A.
Published: June 2007

The effects of voltage, temperature and time on ceramic dielectrics are summarized and general relationships
between formulation, permittivity and stability are described. Factors affecting the electric strength of ceramics are
outlined and suggestions made as to the breakdown mechanisms involved both within the ceramic and at the
ceramic surface. The article is concluded with a description of commercial production techniques employed to
overcome the potential hazards reported earlier.
Electrolytic Rectification and Cathodic Charge Reversibility of Some Valve Metals
Authors: Dyer C. K.
Published: June 2007

Optical studies and observations of electrode cathodic charge reversibility suggest a bulk rather than local effect in
the electrolytic rectification behaviour of Ti and Nb electrodes. The proposed model involves reversible
incorporation of hydrogen into the surface oxide films where it acts as a donor impurity. Applicability of the model
to Al and Zr electrodes is discussed.
Towards a Better Understanding of Screen Print Thickness Control
Authors: Horwood R. J.
Published: June 2007

In recent years, a more scientific approach to the age‐old craft of silk screen printing has resulted in the evolution of
complex precision‐built printing machines for use in the electronics micro‐circuit industry. Even so, our knowledge
of the physical processes involved in screen printing is still far from complete. An attempt is made here to provide a
better understanding of the screen printing mechanism and more specifically of print thickness control. Two
different printing modes are described and the effect of and interaction between some of the more important
machine parameters in this respect are discussed. A simple pillar theory is offered which allows a prediction to be
made of the quantity of ink fundamentally deposited by a given screen.
Wire Wrapped Joints—A Review
Authors: Sollars P. M. A.
Published: June 2007

The basic technique of wire wrapping is now well established as a simple and reliable method for joining conductor
wires in a permanent, though easily replaceable, manner to more massive terminals. This paper describes the
mechanical and the metallurgical basis of the joining technique and outlines the advantages. The scope of the
technique as it has developed up to the present day is discussed in terms of the ranges of wrapping terminals and
wrapping wires used and the types of wrapped joint that have been evolved. Finally the tools available for wire
wrapping are briefly reviewed with particular emphasis on the wrapping bit.
Research and Development in the Field of Passive Components
Authors: Campbell D. S.
Published: June 2007

This paper firstly examines the market situation in passive components in relation to the total position of the
electronics industry. Expenditure on research and development is then discussed and examples given of recent and
present research and development activities in the field of passive components. The situation with regard to the
publication position on research and development in passive components is briefly considered and it is concluded
that there is a positive need for a journal covering the passive component field and acting as an outlet for papers
generated in this area.
Frequency Spectrum Generated by Thyristor Control
Authors: Hall J. K. , Jones N. C.
Published: June 2007

This paper describes the measured harmonics in the load currents of thyristor circuits and shows that with firing
angle control the harmonic amplitudes decrease sharply with increasing harmonic frequency, but that they extend
to very high harmonic orders of around 6000. The amplitudes of the harmonics are a maximum for a firing delay
angle of around 90°.

Integral cycle control produces only low order harmonics and sub‐harmonics.

It is also shown that with firing angle control apparently random inter‐harmonic noise is present and that the
harmonics fall below this noise level at frequencies of approximately 250 KHz for a switched 50 Hz Waveform and
for the resistive load used. The noise amplitude decreases with increasing frequency and is a maximum with 90°
firing delay.
Laser Trimming of Thick Film Resistors
Authors: Dyson A. F. , Cable A. J.
Published: June 2007

Recent papers and conferences, e.g. Ref. 1, have indicated very strongly that thick film screen processing has
become a routine production item, with the specifications and economics being considered in detail. 2The existing
resistor and conduction materials and processes have become well documented3,4 and are well known on an
international scale. This paper reviews the present situation and, in particular, discusses the effects of a
recently‐introduced production tool – the laser trimmer.
Anodic Oxidation of Porous Aluminium Pellets
Authors: Bernard W. J. , Fresia E. J.
Published: June 2007

The anodization of porous aluminum pellets is accompanied by a change in the composition of the electrolyte
within the pellet pores. This change can be accounted for by electrochemical transport of ions to the electrodes and
the inability of the system to overcome the concentrating effects in the anolyte. It is shown that this effect can,
depending on the composition of the bulk electrolyte, result in a strong acid environment or a weakly conducting
electrolyte within the pellet. Either condition results in undesirable oxidizing characteristics; a strong acid will lead
to the formation of a porous film which is poorly impregnated by the solid electrolyte, and the resistive electrolyte
impedes the growth of oxide film. This work indicates that these extreme conditions may be avoided by the use of
electrolytes containing salts of organic acids of moderate strength.
Numerical Evaluation of the Resistivity of Polycrystalline Metal Films With the Mayadas‐Shatzkes Model
Authors: Mola E. E. , Heras J. M.
Published: June 2007

Numerical Tables are given in order to allow a direct comparison of the electrical resistivity model for
polycrystalline films proposed by Mayadas–Shatzkes with experimental data.The tables have been calculated extending the Gauss method for one variable to many variables.
Indirect Heating Source for Treatment of Malignant Brain Tumours
Authors: Thackray Philip C. , Meiksin Zvi H. , Wolfson Sidney K. , Selker Robert G.
Published: June 2007

The design of an indirect heating source for the treatment of malignant brain tumors is presented. A high Q resonant
tank working at 25 kHz generates a magnetic field of 16,000 ampere‐turn/meter (peak) which is used to heat
metallic implants by a combination of hysteresis and induced current heating. The resonant tank is used in a
feedback loop of the power driver to maintain the driver at the resonant frequency, thus minimizing the power
losses that inevitably occur in open loop systems due to reference oscillator drifts and/or varying load and tank
conditions. Because of the high field strengths required and the relatively small power dissipation that occurs in the
metallic implants, the overall system design differs substantially from standard induction heating applications.
Interpretation de Certaines Proprietes de Films Granulaires de Nickel
Authors: Monchaud S. , Rolland S. , Granger R.
Published: June 2007

Des films granulaires de nickel (grains de 100 Å environ) sont obtenus par évaporation sur substrat d′alumine en
ultra‐vide puis recouverts d′une couche d′alumine. La structure et la conductivité électrique de ces grains sont
étudiées. La mise en oeuvre de l′analyse par rétrodiffusion d′ions Hélium et les examens au microscope électronique
permettent d′estimer les effets d′une oxydation thermique sur ces condensats.

Granular nickel films (mean particle size 100 Å) are obtained through evaporation on alumina substrates under high
vacuum then coated with alumina. The structure and conductivity of these films are studied. An estimation of the
oxidation of the nickel particles has been obtained through electron miscroscopy and Helium ion back scattering.
The Use of Hybrid Microelectronics in the Construction of Ion‐Selective Electrodes
Authors: Leppävuori S. I. , Romppainen P. S.
Published: June 2007

The application of hybrid microelectronic manufacturing techniques to the construction of ion‐selective electrodes is considered. A solid state pH glass electrode has been manufactured using thick film techniques. The electrode structure studied consists of a conductive and a glass layer on a substrate. Major problems associated with the making of the pH–sensitive glass paste and the choice of conductive layer material are discussed. With the correct choice of materials and by using a suitable manufacturing process a linear electrode response can be achieved.
Surface Mounting of Leadless Chip Carriers on Various Printed Circuit Board Type Substrates
Authors: Lang I. G.
Published: June 2007

The effect of extended thermal cycling on the reliability of joints between ceramic leadless chip carriers and various printed circuit board type substrates is examined. Test results indicate success in using ceramic leadless chip carriers on some styles of PCB.
Experimental and Theoretical Characterization of Thick and Thin Films for Microwave Uses on 99.6% Alumina Substrates
Authors: Ramy J. P. , Schnitzler R. , Thebault C.
Published: June 2007

In a previous paper,1 we showed, with a microwave quality factor (Q) measurement, that in the X band and with alumina substrates, thick film losses are not worse than thin film losses when the inks are screened then etched, and when they have copper oxide as adhesive layer and gold or copper as metal powder.

Here, we extend this study to show that, our experimental results being in good agreement with theory, a simple D.C. resistivity measurement is sufficient to characterize these MIC′S metallizations and is as suitable as a microwave Q measurement. We also show that the nature of the ground plane cannot be neglected.
Evaluation of Du Pont Copper‐Compatible Resistor System
Authors: Coleman M. V. , Gurnett G. E.
Published: June 2007

Four nitrogen‐fireable resistor inks with resistivities from 20 Ω/□ to 10 kΩ/□ were examined and found to be based upon lanthanum hexaboride. The firing conditions, especially the peak temperature value and oxygen content, considerably affected both the fired resistance value and the shape and slope of the TCR curve. Titanium monoxide was present in the low value resistivity inks and had the effects of modifying the TCR curves in the room temperature region. The stability of the resistor system, especially after ageing at elevated temperatures, was found to be comparable with that of the ‘Birox’ 1400 resistor system. The resistance generally increased in value and the rate of change of
resistance could be approximated to a square root of time law consistent with a diffusion mechanism.
Computer Simulation of Hybrid Integrated Circuits Including Combined Electrical and Thermal Effects
Authors: Zimmer Carl R.
Published: June 2007

This paper describes the application of a modern general purpose network analysis programme SPICE2 for the electrothermal analysis of hybrid integrated circuits. Self thermal coupling effects are modelled using the non‐linear dependent current and voltage source capability in this programme, together with thermal environment parameters obtained from a three‐dimensional thermal analysis program. Although numerical results are given by a bipolar transistor, the method is also applicable to monolithic integrated circuits and to resistors with variable temperature coefficients as power dissipating elements.
Enamelled Steel Substrates for Printed Circuits
Authors: Kužel R. , Broukal J.
Published: June 2007

The preparation of steel substrates coated with intermediate ground and final ceramic coatings is described. The basic material for the preparation of both coatings is the same kind of special glass. The coatings were thermally treated up to 960℃. The resulting substrates were tested for the usage in thick film technology by applying ruthenium resistor compositions designed for use on ceramic substrates. The resistors were fired up to 900℃ and their resistance and TCR were measured. They showed almost the same dependence on firing temperature as the resistors printed on alumina substrates. The TCR was only shifted towards more positive values.
Computer Aided Design of Hybrid Circuits
Authors: Ferraris G. P. , Cagnin T. , Francese F. , Piana L.
Published: June 2007

A system (hardware/software) has been implemented which makes it possible, taking advantage of existing programs with the addition of suitable interfaces and appropriate software modules, to automate the design of thick film hybrid circuits.

This system, named FLASH (Fast Layout Approach System for Hybrids), tends to optimize circuit production yields, by basing the design on their degree of complexity in relation with the printing/firing/trimming cycle.
An Original Interconnection Technique for an Electronic Payment Card
Authors: Monnier M. , Monneraye M.
Published: June 2007

This paper intends to illustrate, through a practical application, the possibilities of LEP foil flexible circuitry for mounting and interconnecting integrated circuits. This technique results in a high density packaging which is used here for the integration of two components, a microprocessor and a memory, in an electronic payment card.
A Large Scale Hybrid Thermal Print Head
Authors: Saito Tamio , Fukumoto Yoshikatsu , Mizuguchi Mamoru , Abe Takahiko , Nagashima Masayoshi
Published: June 2007

A high speed direct drive thermal print head, which prints across a 216 mm wide paper using 1728 heating resistor dots (8 dots/mm) has been developed.

It can print 30 cm long paper in only a few seconds. The head consists of heating dots, over three hundred LSI chips, a couple of dozen capacitors and multilayer thin and thick film circuit substrate.

The substrate is 240 × 70 mm by 1.0 mm thick conductor line width/space is 50 μ/50 μ. Hybridizing
heating elements, drivers and shift registers on one substrate has made it possible to transmit signals serially into the head.

Therefore, the I/O pin number has become far smaller than the number of dots, which has eliminated intermittent I/O pin disconnection.
Multi‐Chip Module Technology
Authors: Rinne R. A. , Barbour D. R.
Published: June 2007

The paper describes the key design features and outlines the manufacturing process for multi‐chip
ceramic modules used in recently announced IBM products. Emphasis is placed on the thermal
conduction module (TCM) which is used in the IBM 3081 computer and incorporates the most
advanced substrate and module technologies at IBM. The 90 mm × 90 mm TCM substrate contains up
to 32 ceramic layers and typically 130M of impedance controlled wiring to interconnect up to 118
LSI logic and array devices. The TCM is designed to provide a cooling capacity of up to 300W. Key
manufacturing challenges are highlighted.
Density Upgrading in Tape Automated Bonding
Authors: Kurzweil K. , Dehaine G.
Published: June 2007

Bondig technique developed by CII‐Honeywell Bull. The paper describes the geometry of bonding pads at the chip level,
the design and realization of the corresponding high density 35 mm tape and the
interconnection of the chips on the tape (inner lead bonding – ILB). Two alternatives of chip mounting
on the substrate are also mentioned.
Hybrid Circuit for Stimulated Bone Regrowth
Authors: Govaerts R. , Sansen W. , de Dijcker F.
Published: June 2007

A hybrid circuit using a custom‐designed I2L IC for a four‐channel implantable biotelemetry system together with a HF transmitter has been designed. It realises a high‐performance and economical device.
New Single‐Capacitor Simulations of Floating Inductors
Authors: Senani R.
Published: June 2007

Out of various methods of floating inductance simulation known so far GIC‐based methods of floating inductance simulation appear to be more suitable from the point of view of microelectronic application. However, a drawback of such configurations is their noncanonic nature due to the requirement of two GICs and hence two capacitors for simulating a first order impedance. This paper reports new type of FI circuits which require only one GIC and thus employ only one capacitor together with a reduced number of resistors, while retaining the merits of the usual GIC‐approach.
Displays
Authors: Schauer A.
Published: June 2007

A short review is given on new display technologies such as plasma, liquid crystals, light emitting diodes, electroluminescence and electrochromism. It is stated that thin or thick film or hybrid techniques are essential for all the different types of display. Comparing the performance data of displays the advantages, disadvantages, appropriate applications and future developments are described. Finally the display market and its growth are discussed briefly.
New Thick‐Film Microwave Elements for Microwave Integrated Circuits
Authors: Gondek Janusz J. , Wójcicki Marek A. , Cąber Jan
Published: June 2007

The realisation of microwave integrated circuits consisting of numerous elements and components, both passive and active, takes place in steps. Initially, experimental constituent elements are designed and constructed, and only after it is found that they satisfy the operating conditions, can they be integrated into a sub‐system. As a result of this we obtain complicated Microwave Integrated Circuits (MICs). Initially however one has to construct basic MIC elements such as: resonators, filters, couplings, Y branch joints, circulators, etc. During research over several years carried out at the Microelectronics Department, Institute of Electronics, of the Mining and Metallurgical University of Kraków and devoted to the application of thick‐film technology to MIC, the authors have devised and constructed several microwave elements using strip‐lines and this paper reports of the results of their studies.

Pastes produced by DU PONT/USA were used. New mathematical models for designing thick‐film microwave elements have been elaborated using computer techniques. These programmes have differed from analogous ones for MIC realized by thin‐film technology can be adapted, after certain modifications, to the realisation of MIC. The authors have introduced new technological operations, not used so far, to the technological process. This has made possible the production of thick‐film microwave elements with parameters comparable to those obtained in thin‐film technology.
Fabrication of Schottky‐Barrier Diodes Using a Thick Film Technique
Authors: Sarin R. , Pradeep Y. R.
Published: June 2007

Schottky‐barrier diodes have been fabricated using a thick‐film technique. A change in V–I characteristic with firing temperature has been observed. This technique is compatible with hybrid circuit technology.
The Use of the Non‐Contacting Temperature Measuring Techniques inthe Early Detection of Hidden Faults in Electronic Components
Authors: Trägner P.
Published: June 2007

One of the reasons for a reduction of production quality is the so‐called ‘hidden faults’, i.e. defects which will not be detected by the available testing equipment in spite of measures for ensuring a good quality. These testing methods, which are mostly electrical, can be supplemented in a suitable way by non‐contacting temperature measuring techniques, since the variation of temperature as a function of operating conditions and environment constitutes one of the most important problems in the design of electronic components and
sub‐assemblies, and of their reliability.

In this paper a relation is presented between a qualitative diagnostic model, reserve stability and other characteristics, on the one hand, and the permissible thermal energy that can be radiated, on the other hand, which facilitates the detection of hidden faults.
Analysis of Thin Film Fire Sensors
Authors: Zentai G. , Illyefalvi-Vitéz Zs.
Published: June 2007

The detection of fire in mines, industrial buildings, ships etc. is an important problem from both the economical and life‐protecting aspects. The fire could be detected in several ways, e.g. by the measurement of flame‐radiation, heat, pressure, temperature, the aerosols, the gases etc.

The Department of Electronic Technology has developed a fire sensor which detects the rate of the increase of temperature. The fire sensor consists of two temperature sensitive resistors with different time‐constants. If the increase of temperature in consequence of the fire is fast, the difference between the resistance of the temperature sensors is high, while a slow change in temperature causes only small differences. By connecting the temperature sensitive sensors into a bridge, the resistance difference can be easily detected.

The temperature sensitive resistors are realized by thin film technology using platinum or nickel film on a thin glass or ceramic substrate. Because of the large surface and small volume of the resistor, its time‐constant originally is very low but the time‐constant could be easily increased by increasing the volume of the resistor. The present paper gives a detailed description of the analysis and the measurement of the temperature sensitive
resistors with different time‐constants. The technology of the films is also discussed.
Methods of Checking Printed Circuits
Authors: Hajdu I. , Bánlaki P. , Pinkola J. , Tóth E.
Published: June 2007

Printed circuits make up to 20 to 40 per cent of the value of electronic circuits.

Quality and reliability requirements have been boosted by the general use of complex integrated circuits. An economical and high quality production is preconditioned by the continuous checking of prime materials and technologies.

After a brief review of checking methods, a short examination of quality testing of the end product (double ‐ or multilayer printed circuit board) is given, involving checking methods of assembled and non assembled boards.
Examination of Thick‐Films Using Modern Surface Analytical Techniques
Authors: Harsányi G. , Ripka G.
Published: June 2007

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.
Usage of Sims and Auger Test Methods in the Production of MultilayerPrinted Circuit Boards
Authors: Toth E. , Banlaki P. , Hajdu I. , Pinkola J.
Published: June 2007

The quality and reliability of multilayer boards are determined by the adhesion strength between the copper sheets and the epoxy‐glass laminates. The adhesion properties of copper foil may be improved by mechanical or chemical roughening. The most efficient method is, however, to oxidize the copper surface.

Oxidized copper layers have been tested by thermogravimetry. Subsequently the oxide layers have been tested by Auger and SIMS techniques. The results showed that the main constituent of the oxide layer produced in a sodium hypochlorite type electrolyte is Cu20.
Scratch‐Profiles Study in Thin Films Using SEM and EDS
Authors: El-Shabasy M. , Pogány L. , Konczos G. , Hajtó E. , Szikora B.
Published: June 2007

The adhesion of evaporated or sputtered thin films to substrates is one of the most important characterising parameters in their fabrication. It is a conventional method to scratch the films using a stylus and evaluate the shearing stress, which is proportional to the energy of adhesion. For the evaluation it is necessary to determine the so‐called critical load and the profile of the scratch.

The aim during this experimental work was to find a method to evaluate the scratch profile from the X‐ray‐line profile and SEM pictures. From SEM pictures, the lateral dimensions and surface morphology of the scratches were studied. The thickness was also studied from X‐ray‐line profiles.

In this paper the thickness profile measuring method and the conclusion for the scratch method are discussed.
Inaccuracies of Measuring Methods and Their Influence on the Regression Function
Authors: Sauer W.
Published: June 2007

The quality parameters of electronic components and devices usually depend on the parameters of the materials. In many cases one does not know the theoretical relationship between the parameters, and therefore one makes technological experiments and measures the values of the parameters. Usually it is necessary to take several measuring points and calculate from this the unknown relationship between the parameters.

The simplest equation that one can use is the linear function. In this case the theoretical probability density function is a Gaussian‐function. Otherwise it is necessary to assume that the linear function is an approximation.

When the measuring process has an inaccuracy, then one can show that the increase of the linear function is smaller and it is necessary to estimate a factor of correction to calculate the theoretical or exact relationship.
Reliability Compliance Testing of Electronic Components for Consumer Electronics
Authors: Przybyl E. , Peciakowski E.
Published: June 2007

In this paper the organisation of reliability compliance testing of electronic components in Poland is discussed. The aim of the testing is to find the reliability of the components to both producer and user and hence to establish reliability for the two parties. The system described is derived from standard methods and has two aims. These are:‐

1) To enable periodical checks of production to be made.

2) To estimate the reliability level of the components produced.

Sampling plans are constructed on the basis of Weibull distributions. Individual life tests are performed to compare the reliability levels with those in the specification, and also to enable data to be accumulated for calculation of average failure rates. These tests are supervised by the quality centre UNITRA‐ELECTRON. The centre is then in a position to provide reliability data on electronic components for the designers and producers of electronic equipment.

The system of reliability compliance testing given in the paper will be effective if the tests are
performed frequently. The aim is also to achieve results in the shortest possible time. In order to achieve these aims accelerated life testing has been investigated.

Applicability of techniques, including that of accelerated life testing, to the study of reliability of
polyester capacitors is examined.
Optical Fibre Connectors for Harsh Environments
Authors: Challans J. C.
Published: June 2007

This paper describes the construction of a multiway Optical Fibre connector suitable for harsh environments, based on a ruggedised marine connector (Patt 608) shell, and employs expanded‐beam principles. The connector utilises an array of sapphire sphere lenses force‐fitted into a metal plate forming a flat mating surface with all the precision parts protected behind the lenses.
A Short Communication — Determination of Chip and Substrate Temperatures
Authors: Haskard M. R.
Published: June 2007

Through making use of the analogy between electrical current and thermal heat flow, thermal calculations for thick film substrates may be undertaken using standard computer aided design programs such as SPICE 2. Chip temperature and substrate isotherms for various conditions can readily be determined. Parameters considered in this paper are chip position on substrate, with and without heat sink, number of chips on a substrate and substrate materials.
Reliability Assessment and Screening by Reliability IndicatorMethods
Authors: Møltoft Jørgen
Published: June 2007

Built‐in flaws in electronic components have been recognized as a serious cause of failure. They are difficult to screen away by conventional methods because the times‐to‐failures for component working in systems are often rather long and because accelerated burn‐in may screen by the wrong failure mechanisms. As an alternative, the concept and possible use of reliability indicator methods are discussed and some recently developed methods described.
Mid‐Film Interconnects for Multilayer Microcircuit Packages
Authors: Sue R. , Naguib H. M.
Published: June 2007

The mid‐filmR process has been developed to combine the photolithographic capability of thin film technology and the low cost, non‐vacuum processing of thick film technology. In this paper, we present results on the characterization of mid‐film gold for multilayer applications. The effects of various processing parameters on the properties of the conductor were investigated to establish optimum processing conditions on alumina and dielectric‐coated alumina substrates. The use of a resin thickness in the range from 5 μm to 15 μm and firing temperatures from 750℃ to 1000℃ produced conductor lines with sheet resistances less than 4 mΩ/□, and with adhesion strengths capable of with‐standing
a pull force of 2.3 Kg exerted on a 2.03 mm × 1.03 mm area. The conductor lines exhibited
stable resistances upon several firings at 920℃. The ultrasonic bondability of 25 μm (1 mil) aluminum wire to the mid‐film gold was observed to withstand pull forces of 7.3 ± 1.5 g before breaking the bond. In addition, it was confirmed that the resolution limit of the mid‐film conductor is 50 μm for
line widths and spaces. Furthermore, the prototype fabrication of a multilayer memory package has been successfully demonstrated using a combination of both mid‐film and thick film processes. The finished packages were free of electrical shorts and conductor discontinuities and the resistance of the mid‐film conductor lines was well within the required design specifications.
Expression de la Tension Photovoltaïque Induite parTransition Interbande Dans des Couches Minces de Sulfure de Zinc
Authors: Tosser A. , Murray H.
Published: June 2007

En considérant les variations dimensionnelles de la tension photovoltaïque induite en circuit ouvert par des
rayonnements lumineux d′énergie supérieure à 3,66 eV dans des structures sandwich Al/ZnS/Au, ainsi que les
variations avec le flux lumineux du courant de court‐circuit et de la conductance correspondant à la phototransition entre bandes, l′hypothèse d′une quasi‐bande de conduction créée par l′ionisation de centres coulombiens est
avancée. Elle conduit à une formulation de la tension photovoltaïque en bonne cohérence avec l′expérience.

Variations with thickness of open‐circuit voltage, short‐circuit current and photoconductance associated to
interband transition lead to postulate the existence of a quasi‐conduction band, associated with ionized coulombic
centres, in Al/ZnS/Au illuminated (photon energy > 3,66 eV) sandwich structures. An expression of open‐circuit
voltage is deduced, in good agreement with experimental data.
Couches Conductrices et Transparentes Obtenues par Pulverisation d′une Cible de SnO2
Authors: Launey J. , Tosser A.
Published: June 2007

SnO2 is reactively r.f. sputtered to obtain conductive thin films of good optical transmission. Data about thermal ageing in vacuum, thermal evolution of conductivity, spontaneous ageing in air and optical transmission show how it is possible to obtain a transmission of 80% in visible light with resistance square below 1 kΩ/sq; the possibility of a multiple‐step process of sputtering is presented. A “nucleation‐growth” model allows an explanation of the observed phenomena.

La pulvérisation haute‐fréquence d′une cible de SnO2 en présence d′argon et d′oxygène permet d′obtenir des couches minces conductrices de bonne transparence optique. A partir des phénomènes de recuit sous vide, d′évolution de la résistance avec la température, du vieillissement spontané à l′air et de la variation de la transparence optique, il est possible de déterminer la méthode permettant d′obtenir un facteur de transmission de
80% en lumière visible et une résistance carrée inférieure à 1 kΩ/sq; l′intérêt d′une pulvérisation fractionnée est explicité. Le modèle de “germination‐croissance” permet une description convenable des phénomènes observés.
The Direct Bonding of Metals to Ceramics and Application in Electronics
Authors: Burgess J. F. , Neugebauer C. A. , Flanagan G. , Moore R. E.
Published: June 2007

The direct bonding of metals to ceramics is possible utilizing a gas metal eutectic. The mechanism of direct bonding of copper foil to ceramics in a slightly oxidizing atmosphere is presented. It involves the formation of eutectic melt between copper and oxygen at a temperature slightly below the melting point of copper, which serves to bring the foil into intimate contact with the substrate. Metals to which technique is applicable include Cu, Fe, Ni, Co, Ag, Cr, Mo and Al. A brief review of other metal–ceramic bonding techniques is given for comparison.

The process for fabricating direct bonded copper structures is given, and properties of the bond are discussed.
The use of the directed bonding process in a number of electronic applications such as hybrid packages and power
device heat sinks is indicated.
Temperature‐stable Barium Titanate Ceramics Containing Niobium Pentoxide
Authors: Burn Ian
Published: June 2007

Niobium is known to lower the Curie point and broaden the permittivity peak of barium titanate. However, the
distribution of niobium in sintered barium titanate is often not homogeneous, being influenced by such preparation
variables as large cation/small cation stoichiometry and firing conditions. In addition to these factors, it was found that, at least up to about 5 mol% Nb, the distribution of niobium in the barium titanate grains could be regulated by small amounts (<1 mol%) of oxides of Co, Mg, Ni or Mn. These oxides appear to form niobates that produce high permittivity solid solutions in the “skins” of the barium titanate grains and permit dielectrics to be obtained with permittivity (), stable to within ±10% over the temperature range −55℃ to 125℃.
Simulation of the Dynamic Transistor Negatrons
Authors: Molchanov Pavlo , Misra Arun K. , Linnik Helen , Mulyar Pavlo
Published: June 2007

The simulation principles of monolithic microwave dynamic transistor negatrons
(circuits with negative differential active resistance) are introduced. The non‐linear
model has been developed on the basis of non‐linear charge model. The equivalent
circuit and Volterra series were used for the calculation of dynamic negatrons′
parameters. The expressions were obtained, which give the linear relation between
current and voltage charges and allow calculating the transferring characteristics.
Experimental oscillators are described, which confirm the theoretical predictions.