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The environmental reliability of Series Q, a system of materials designed for advanced ‘HIC’ circuits, has been studied using three different migration‐resistance tests. —LMRT: a test which is used to assess the resistance to electrochemical migration of horizontally adjacent, closely spaced conductor tracks in a high‐temperature, high‐humidity environment with a voltage bias present (60°C, 90%RH, 48 VDC). —HHBT: a test which monitors the ability of a dielectric to resist electrochemical migration when vertically adjacent crossover conductor tracks are oppositely biased (85°C, 85%RH, 5 VDC). —HBT: a test which measures how well a dielectric can sustain its resistance to voltage breakdown over extended periods of time during continuous exposure to conditions of high temperature and voltage (150°C, 200 VDC). The results show that the QSil™ and QPIus™ systems, the two materials systems that comprise Series Q, demonstrate excellent performance in all three areas. Predictions of how well circuits made from these materials will survive in their operating ambient over the long term, e.g., twenty years, have been made.

Thermal ageing experiments on various thick film resistor systems have shown that resistance change is caused by a number of different mechanisms with different time dependences. Three distinct types of behaviour have been identified: corrosion due to ambient attack; diffusion through resistor interfaces with conductor terminations or through the resistor top surface; and stress relief within the bulk of the resistor. Wherever possible the dominant mechanism has been identified and the activation energy and time dependence of the ageing process have been determined.

Platinum gold conductors, used as solderable terminations, contain a glass frit which reacts with the minority constituents in debased alumina substrates forming an adhesive bond. Some conductor inks also contain copper and cadmium, in addition to the glass frit, which react directly with the alumina to form a chemical bond. Dielectric inks contain a crystalline filler, such as alumina or zirconia, in a glass matrix. The effect on the physical and electrical properties of platinum golds on various dielectrics was examined in comparison with the behaviour on alumina. Composition and surface structure of the dielectric affects the adhesion strength, solderability and solder leach resistance of the conductor inks. Interaction between the glasses in the dielectrics and conductors was determined by analysis in the SEM. Interdiffusion between the conductor and solder metals occurs and brittle intermetallic compounds are formed. The effects of the intermetallic formation on the adhesion strength and modes of failure, especially after thermal ageing at 150°C, have been examined. Thick film resistors printed and fired onto dielectrics rather than onto alumina substrates generally have different electrical properties. Chosen resistor systems, terminated with a gold conductor, were evaluated on different dielectrics. The values of electrical parameters such as resistance, TCR and noise index were compared with those on alumina. Interactions between the glasses in the resistors and dielectrics were examined as for the conductors. Thermal ageing on various resistor/dielectric combinations was carried out in order to determine the long‐term stability. The activation energies and time dependences of the ageing mechanisms for each combination were found. Corresponding ageing equations were calculated in order to predict the likely behaviour during life.

This report discusses the physical, electrical, mechanical and thermal characteristics of polyimide conductive, resistive, and dielectric thick film compositions made for high‐temperature curing and coating on non‐flexible substrates (alumina). The effects of curing times and print direction on sheet resistivity are presented for conductive patterns. The rates of silver migration of silver loaded resins are examined under 100% relative humidity at 25°C and various gap distances. The effect of current limiting resistors on silver migration is also examined. The electrical characteristics of polyimide thick film (PTF) resistors such as temperature coefficient of resistance and drifts are examined. The relationship of aspect ratio versus mean resistance and sheet resistance, as well as distribution diagrams are presented. The printability and definition of conductor patterns relative to their thickness, separation and the direction of the prints are examined, while the electrical characteristics of crossovers such as voltage breakdown are also investigated.

On 20 April ISHM‐Benelux held its 1988 Spring meeting at the Grand Hotel Heerlen. This meeting was totally devoted to implantable devices, in particular to the technologies used for these high reliability, extremely demanding devices. For this meeting ISHM‐Benelux was the guest of the Kerkrade facility of Medtronic. Medtronic (headquartered in Minneapolis, USA) is the world's leading manufacturer of implantable electronic devices. Apart from the assembly of pacemakers and heart‐wires, the Kerkrade facility acts as a manufacturing technology centre for Medtronic's European facilities.

The increasing complexity of hybrid circuits has led to a need for a reliable multilayer system. As well as reliability, the manufacturer will, of course, also attach considerable importance to material and production costs. Until now, thick film multilayer applications have been limited by the inability of existing technology to reduce their susceptibility to galvanic effects occurring between individual conductive layers during fabrication. Now, however, this company has developed a multilayer dielectric which prevents metal migration. The system is supported by conductor and resistor systems.

Complex mixed metallurgy multilayers require a very robust dielectric to withstand shorting or blistering effects, together with high density for long‐term reliability in humid environments. The development and performance of a new multilayer dielectric which meets these needs is presented here. A dielectric frit chemistry has been developed with a view to eliminating short circuits and blistering induced by the proximity of dissimilar metallurgies on multiple refiring. Appropriate filler technology has also been developed to optimise dielectric density, toughness and laser‐trim properties. High density has yielded excellent HBT (High Bias Temperature) and HHBT (High Humidity Bias Test) performance. Data on multilayer circuit bowing are presented which take account of the interaction of conductor frit and the dielectric on firing. Silver conductor is employed in inner layers to optimise conductivity and cost. A new 1:3 PdAg conductor for termination of components and resistors also permits heavy Al wire bonding with good aged performance. 25 µm Au and 37 µm Al wire bonding is facilitated by gold conductor on dielectric. The laser trim characteristics of a new resistor series on dielectric are described. The materials system has been tested in a complex multilayer structure which, with the use of a new silver via fill conductor, resulted in defect‐free circuits with zero yield loss.

To consider the various aspects of this emerging market and to query the traditional view of thick film deposition and processing for successful flexible electronic production.

The current status of flexible electronics is reviewed with particular emphasis on emerging rather than established technologies. New techniques and applications are also discussed. Material and processing developments are also required to meet the new challenges and current developments and future needs are discussed.

Mass production of flexible electronic circuits using processing techniques that are more akin to the newspaper printing industry is under way. Much development of both materials and processing is required but needs in the radio frequency identification, renewable energy and display markets among others justify the investment.

Due to the wide range of new applications there is a lack of detail in this review that will necessitate further reading.

There will need to be a change of thinking in the processing and material choice used in mass production of flexible electronics by any large volume manufacturer of traditional circuits on rigid substrates. Existing, new materials need development for electrical characteristics and ease of use. New materials will undoubtedly be required.

This paper raises awareness and technical issues surrounding emerging technologies.

Building on the notion of “White fragility,” this study aims to explore how Whites react and cope with perceived discrimination at work. Specifically, the authors explore whether: (1) Whites react more negatively than minorities when they perceive discrimination at work and (2) Whites are more likely than minorities to restore the status quo by leaving the situation when they perceive discrimination at work.

Data for this study were obtained from the Professional Worker Career Experience Survey. In total, 527 working professionals from multiple organizations across the central USA participated in the survey.

The authors find evidence that Whites experience more negative psychological effects (i.e. lower job satisfaction and higher work stress) from perceived discrimination than minority employees and are more likely to act to restore conditions of privilege by leaving their current job and employer. The stronger negative effects of perceived discrimination for Whites (vs minorities) were restricted to work outcomes (job satisfaction, work stress, turnover intentions from one's employer) and were not evident with respect to perceptions of overall well-being (i.e. life satisfaction), suggesting that White fragility may play a particularly influential role in work settings, wherein racial stress may be more readily activated.

Consistent with the notion of White fragility, the study’s results demonstrate that the deleterious impact of perceived discrimination on employee work outcomes may, in some cases, be stronger for White than minority employees.

The purpose of this paper is to formulate a framework to construct a patient-specific risk score and therefore to classify these patients into various risk groups that can be used as a decision support mechanism by the medical decision makers to augment their decision-making process, allowing them to optimally use the limited resources available.

A conventional statistical model (logistic regression) and two machine learning-based (i.e. artificial neural networks (ANNs) and support vector machines) data mining models were employed by also using five-fold cross-validation in the classification phase. In order to overcome the data imbalance problem, random undersampling technique was utilized. After constructing the patient-specific risk score, k-means clustering algorithm was employed to group these patients into risk groups.

Results showed that the ANN model achieved the best results with an area under the curve score of 0.867, while the sensitivity and specificity were 0.715 and 0.892, respectively. Also, the construction of patient-specific risk scores offer useful insights to the medical experts, by helping them find a trade-off between risks, costs and resources.

The study contributes to the existing body of knowledge by constructing a framework that can be utilized to determine the risk level of the targeted patient, by employing data mining-based predictive approach.