Technical Library | 2017-11-30 10:29:29.0
Each year the electronics industry is faced with new product designs that call for smaller printed circuit boards (PCBs) to function in more aggressive and rigorous service environments. As demands change, conformal coating is becoming increasingly adopted to ensure PCB reliability in environments where moisture, condensation, dust, dirt, salts, chemicals, abrasion, thermal shock, mechanical shock, and other factors can all affect circuit performance. This guide reviews the benefits of using light-cure conformal coatings as well as cost justification, typical processing guidelines and best practices, product selection criteria, data, and industry specifications.
Technical Library | 2018-08-08 21:55:00.0
180 °C and Td >400 °C. In addition to a high thermal stability, Material A also shows a dielectric loss factor lower than commercial phosphorus-based flame retardants.
Technical Library | 2007-04-04 11:43:41.0
The present work offers a discussion and a first case study to identify and illustrate voiding mechanisms for a particular TIM between a heat spreader and the back of a flip chip. Pronounced differences were observed between stencil printing and dispensing in terms of initial void formation, apparently related to the specific properties of the material. Measurements of the effects of heat ramp rate and peak temperature showed the subsequent evolution and final void size distribution to be determined by the initial part of the cure profile up to the material gelling temperature.
Technical Library | 2013-01-09 18:31:54.0
The increased temperatures associated with lead free processes have produced significant challenges for PWB laminates. Newly developed laminates have different curing processes, are commonly filled with ceramic particles or micro-clays and can have higher Tg values. These changes designed to reduce Z-axis expansion and improve the materials resistance to thermal excursions through primary attach and rework operations have also produced harder resin systems with reduced fracture toughness.
Technical Library | 2020-02-14 14:43:21.0
To meet the steady increase in technical requirements for electronic components, potting media properties must be extremely precise. Rheology, viscosity, filler content and curing behavior are only a few of the factors that play a role in their practical use. However, the growing complexity of materials often negatively impacts the ability to process or dispense them. In this case, material preparation and feeding systems specially designed for this purpose are required. These systems optimally prepare the material for the actual application and ensure homogeneous feeding to the dispensing system.
Technical Library | 2021-08-11 01:00:37.0
Conformal coatings and potting materials continue to create issues for the electronics industry. This webinar will dig deeper into the failure modes of these materials, specifically issues with Coefficient of Thermal Expansion (CTE), delamination, cracking, de-wetting, pinholes/bubbles and orange peel issues with conformal coatings and what mitigation techniques are available. Similarly, this webinar will look at the failure modes of potting materials, (e.g Glass Transition Temperature (Tg), PCB warpage, the effects of improper curing and potential methods for correcting these situations.
Technical Library | 2022-10-11 20:15:14.0
The increased temperatures associated with Pb-free processes have produced significant challenges for PWB laminates. Newly developed laminates have different curing processes, are commonly filled with ceramic particles or micro-clays and can have higher Tg values. These changes which are aimed at improving the materials resistance to thermal excursions and maintaining electrical integrity through primary attach and rework operations have also had the effect of producing harder resin systems with lower fracture toughness.
Technical Library | 2016-05-19 16:03:37.0
As consumers become more reliant on their handheld electronic devices and take them into new environments, devices are increasingly exposed to situations that can cause failure. In response, the electronics industry is making these devices more resistant to environmental exposures. Printed circuit board assemblies, handheld devices and wearables can benefit from a protective conformal coating to minimize device failures by providing a barrier to environmental exposure and contamination. Traditional conformal coatings can be applied very thick and often require thermal or UV curing steps that add extra cost and processing time compared to alternative technologies. These coatings, due to their thickness, commonly require time and effort to mask connectors in order to permit electrical conductivity. Ultra-thin fluorochemical coatings, however, can provide excellent protection, are thin enough to not necessarily require component masking and do not necessarily require curing. In this work, ultra-thin fluoropolymer coatings were tested by internal and industry approved test methods, such as IEC (ingress protection), IPC (conformal coating qualification), and ASTM (flowers-of-sulfur exposure), to determine whether this level of protection and process ease was possible.
Technical Library | 2010-02-10 23:50:23.0
The electronics industry has recently undertaken the transition to lead-free processing as a direct consequence of the RoHS directive, which came into force in July 2006. However, this is unlikely to be the last transition required since the European Solvent Emissions Directive, 1999 is starting to be implemented and enforced by national governments. This is resulting in pressure on larger manufacturers, currently emitting more than 5 tonnes of solvent vapour per annum to take steps to limit and reduce their emissions.
Technical Library | 2006-10-26 08:08:00.0
There have been many studies of the causes of tombstoning; some published, some not. They tend to focus on a single process parameter as the root cause of tombstoning. However, there is no single process change that is a sure cure for tombstoning! Those that claim otherwise are either uninformed or trying to sell you something. Rather than limiting your view to a single solution, EFD recommends you heed all of the studies. Like pieces of a puzzle, each study does not reveal the whole picture, but looked at all together, the picture is clear.
Reflow ovens for automated SMT PCB assembly, specializing in lead free processing and nitrogen reflow. The best convection reflow ovens on the market.
4 Vreeland Rd.
Florham Park, NJ USA
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