The Electronics Interconnection Group’s webinars are now in their 8th year. The Group is internationally recognised for its practical and innovative work on lead-free reliability, PCB interconnection failures, tin whisker migration and conformal coating research.

The team investigate interconnect properties and develop metrological techniques to characterise performance, frequently in multiple domains. Our research is focused on the emerging technologies within printed electronics, harsh and high temperature electronics, wearable technology and electrochemical performance in coating barrier systems

Increasing the Performance of Organic PCBs at Higher Temperatures - 17th January - 2.30pm UK Time

Presented by Martin Wickham

Book your place here: https://attendee.gotowebinar.com/register/4089708661063184898

There has been an increase in the demand for high temperature interconnect solutions at circuit board level joining with recent introductions of high power semiconductors and increased operating temperatures. Application areas for these new devices include electric vehicles, renewable energy, avionics and oil and gas. Reliable operation in these environments requires a combination of performance improvements in components, interconnects and substrates. At higher temperatures (above 200oC), ceramic based substrate options tend to dominate over organic resin based systems. They can also be costly, heavy and prone to mechanical damage. The National Physical Laboratory has undertaken several projects to better understand the performance enhancements required in interconnection materials to operate reliably in these harsher environments. The collaborative project with industry has developed a coating system for organic matrix PCBs, designed to operate at 250oC. The results show a significant improvement of mean-time-to failure (MTBF) for coated PCAs and PCBs compared to uncoated samples. The primary performance improvement is shown to be reduction in the oxidation rate of copper in both the inner and outer layers of tracking in the multilayer structures

Organic Hybrids for Circuit Assemblies – Initial Environmental Testing of a Low Cost Alternative to Ceramic Substrate Based Assemblies - 19th March - 2.30pm UK Time

Presented by Martin Wickham

Book your place here: https://attendee.gotowebinar.com/register/7286951035682421506

There are an increasing number of electronics applications in aerospace, automotive, shale/gas and power management, which are required to operate at or above 200 oC. Organic matrix reinforced substrates such as polyimide, have maximum operating temperatures in the region of 175 oC. Reliable operation of electronics at temperatures higher than this requires a combination of performance improvements in components, interconnects and substrates. Ceramic substrate options are based on alumina substrates with printed inks fired at ~ 600 oC and can be costly, heavy and prone to mechanical damage. Printed circuit board (PCB) options are restricted to lower working temperatures of the organic resins and degradation of their conductive copper tracks through oxidation. This webinar highlights earlier work undertaken by the authors and partners to understand the deficiencies of copper- clad PCB technology and details work to develop a low cost alternative to ceramic substrate based assemblies.

NPL and its project partners have investigated replacing the alumina substrates with high temperature engineering thermoplastics such as PEEK. The high temperature fired inks conventionally used in hybrid circuit manufacture have been replaced with screen-printable silicone based ink systems curing at 250 oC. The specially developed electrically conductive and dielectric inks were utilised to produce a multilayer system demonstrator with high temperature compatible components attached using a high temperature conductive adhesive. Such an assembly system has the potential to benefit from reductions in substrate cost and assembly weight. Energy cost associated with manufacture are significantly reduced. In addition the organic substrate is easier to machine and form into complex shapes and offers the possibility of integrating thermal management solutions. Environmental testing has been undertaken to determine the suitability of the system to operate for extended periods at 250oC and the results of the electrical and mechanical performance for continuous ageing of test assemblies at 250oC will be given

Evaluation Of Embedded Electronics For Use In Harsh Environments - 21st May - 2.30pm UK Time

Presented by Dan Flintoff

Book your place here https://attendee.gotowebinar.com/register/3632023751905894913

The ongoing trend of miniaturisation in the electronics industry has been focused on the reduction in size of components and component packaging. However, with an inevitable limit due to manufacturing capability, an alternative is required. Device embedded substrates are a promising solution which looks at miniaturisation from a substrate perspective, using a 3D approach to circuit design by placing components into the substrate as well as on the surface. This manufacturing method has been shown to increase circuit density, reduce signal paths, and reduce parasitic capacitances and inductances. Devices containing embedded components are already on the market but have yet to be evaluated fully for use in harsh environments

NPL’s work in this area, in collaboration with the University of Surrey, is looking at the reliability of embedded electronics to evaluate them for use within harsh environments through the creation of a test vehicle which was designed for testing of the reliability of the interconnect structures connecting the components. This is being achieved through the use of NPL’s harsh environment test facilities. The ongoing testing, for example thermal cycling from -55°C to +125°C, will indicate the structure’s suitability for use in harsh environments. Testing will also provide an insight into adaptations required in the standard testing parameters for industry

Effect of Bias (up to 1000V) on Conductive Anodic Filament (CAF) Failures of Electronic Circuits - 16th July - 2.30pm UK Time

Presented by Ling Zou

Book your place here: https://attendee.gotowebinar.com/register/3014133401444469762

Achieving high reliability in service is the key issue in today’s high density electronic circuits. The voltage applied to the electronic circuit plays a very important role in electrochemical reliability. Insulation Resistance (IR) measurement has been widely used to predict and evaluate the reliability of electronic circuit. The test voltage for existing IR measurement are only up to 300 V. Trends for more electric vehicles mean that the measurements need to be conducted at significantly increased voltages to understand potential new failure mechanism when using voltages up to 1000 V. NPL has commissioned a 1000 V IR test facility. CAF formation inside PCBs is an important failure of the electronic circuit. Special designed PCBs with CAF patterns of different via to via distances will be tested at different voltages up to 1000 V. 1000 V AC voltage will also be tested. The relationship between via to via distance and test voltage of CAF failure will be investigated

Electrical and Thermal Material Evaluation Using Power Cycling Testing For Power Electronic Applications - 17th September - 2.30pm UK Time

Presented by Adam Lewis

Book your place here: https://attendee.gotowebinar.com/register/137166669368627714

There is an ongoing rapid growth in the market for electric and hybrid vehicles. As this technology develops, the operating voltage and current draw of these systems increase to meet end-user requirements. Both of these factors (the higher voltage and higher current) can lead to a range of failure mechanisms. It is important that the reliability of these systems is well understood and can be appropriately tested/investigated. In the near future this technology will move onto electric aircraft where reliability plays is a key consideration in the design.

At NPL we have recently run a project investigation the electrical and thermal degradation of power modules, evaluating their performance from a materials aspect. We have developed our power cycling capability enabling us to heat power module systems at device level leading to local heating. Using active cooling, we are able to rapidly cycle the device temperature and accelerate lifetime testing to evaluate the performance of the electrical interconnects and the thermal interfaces in the device stack

Battery Metrology At NPL – Lithium Ion Cell Characterization - 12th November - 2.30pm UK Time

Presented by Kate Clayton

Book your place here: https://attendee.gotowebinar.com/register/6218401655388449793

In 2017 the Government announced the end to sales of new conventional petrol and diesel cars and vans by 2040 to reduce carbon emissions and the associated negative health effects from poor air quality. Electric vehicles (EVs) are expected to provide an alternative solution to the ban, however increasing sales in EVs requires an improvement in consumer confidence. The government have announced to make over £600 million of funding available to support the uptake and manufacture of ultra low emission vehicles with an investment of £246 million to support the development of new battery technologies. Research in battery technology is a growing area with lithium ion chemistry set to dominate the electric vehicle market in the short to medium term due to its high energy density and low self-discharge properties. However the need for improvement is great with focus directed towards lowering cost, improving performance and increasing the safety of the battery. Success in these areas is expected to open a competitive market, improve consumer confidence and increase the uptake of EVs on the road. Battery metrology is a strategic focus for NPL and pivotal for the realisation of zero emission vehicles. Register for this talk to hear about the facilities at NPL available for lithium ion battery metrology, our capability in this area with a focus on using electrochemical impedance spectroscopy to evaluate the battery system and the research that we have been doing upon nickel manganese cobalt (8:1:1) and graphite electrode materials.