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LED Protection A Design Engineer's Guide

The LED market must surely represent on the list of fastest growing sectors while in the electronics industry and LEDs now are utilised in all of the different types of lighting, signage and domestic appliance products. LEDs offer several benefits over traditional lighting available as adaptability, lifetime.

Specially designed and formulated chemicals are trusted while in the electronics niche for a colossal number of applications. Be it during PCB manufacture and the safety of components or complete devices, such products are getting to be a vital consider ensuring the performance and quality of technology.? Specially in LED applications such products enables you to assist Design Engineers in protecting LED systems in numerous conditions, for example the setting up lighting designs in corrosive environments, including. Mainly because of the design freedom that LEDs offer, applications have gotten more diverse and challenging consequently, aesthetic results has to be achieved with the consideration of reliability and lifelong on the product. In addition, specialist chemicals could also be used as part of the design for cosmetic reasons in addition to helping provide key functional improvements just like increased efficiency and reduced energy consumption.

Enhancing Performance in Challenging Environments

Jade Bridges, Global Tech support team Manager, Electrolube Ltd

The environment how the LEDs and associated electronic components are utilized in could have an effect on the species of product required to protect the program assure reliability. Environmental challenges is often in the form of corrosive environments; when moist, salt mist or corrosive gases exist, as an example. As a consequence of potential range of LED applications it’s also entirely possible that UV exposure, water immersion or chemical exposure might make up area of the operating environment. Therefore, it’s imperative that your end use application is fully understood in order that the correct protection media is applied.

Where protection directly covering the LED becomes necessary there are various of points that need considering. The clarity on the material applied is extremely important to making sure maximum utilisation regarding output with the LED. Also, any potential changes to your colour temperature, clarity with the material or light output of the LED during operation must be considered. Protection is usually offered as conformal coatings or encapsulation resins, using the choice backward and forward being driven by the severity of the operating environment as well as the desired aesthetic effect.

To discuss this in greater detail, some example applications can be viewed as. LED signage may be a growing rapidly industry, with LEDs offering more methods of design and also providing affordable and efficient interactive displays. Based on the place that the sign is scheduled as well as the model of the machine, the condition of exposure to environmental conditions can differ. A roadside sign, for instance, is sealed from the elements (usually in an IP rated case) but the possibility for moisture ingress and condensation forming to the board still is apparent, particularly because of the changing temperature conditions. The condensation can also have some salt content for you can be prolonged experience UV light. Bills ., we will expect an acrylic conformal coating, such as Electrolube’s AFA, to provide the required protection against humidity and salt mist whilst also maintaining its clarity after experience of UV light. Consideration in the unit design and probability of standing water forming within the PCB must be treated; if water would have been to constantly go beyond the board or ingress into the unit in time, the protection level required may increase.

Another example include the using of LED signage where expertise of corrosive gases could be possible. Corrosive gases can penetrate through coatings and so on with the LED lens, discolouring the LED chip and as a result, dramatically lowering the light output and efficiency with the LED. Thus, the amount of contact the corrosive gases is vital. For a pricing join a fuel station, you may find that your fumes radiated will not be concentrated enough to affect the LEDs in the forecourt display and therefore, a conformal coating might be recommended to guard contrary to the general environmental conditions as discussed above. However, in case where corrosive gases are mixed together in high concentrations, an even more sufficient barrier is required. Applications for instance industrial lighting or lighting for agricultural or livestock environments will surely have to use encapsulation resins to make sure corrosive gases present never penetrate high on the LED while in the lifetime of the product. The subsequent graph indicates the different stages of protection expected from various coatings and encapsulation resins; it is very important realize that silicone resins are permeable to gases, which means the poor performance such applications.

Other LED applications occasionally includes those that require some physical protection and also providing a barrier to environmental influences. A good example application is LED strip lighting for floor luminaires in the shopping complex. The luminaires usually are functional and the main aesthetic variety of the complex and may have a higher level of traffic passing directly covering the resin used to protect the LEDs inside the unit. Firstly, a conformal coating will not likely offer the physical protection required resulting from it being used for a thin film (<200 microns). When thinking about encapsulation resins rather, it may be assumed that your tough epoxy would provide the best physical protection with the unit. However, there are two aspects to consider using this product selection; UV exposure and cosmetic wear on the resin. Most standard epoxy resin systems will degrade when come across UV light, as shown inside image below.

For this application, the luminaires are installed both internally and externally and thus must be UV resistant. On top of that, the epoxy systems less complicated harder and often show signs and symptoms of wear much clearer, due to the capacity to scratch/key the top of resin. For these reasons, we’d recommend a polyurethane based resin, which include Electrolube’s UR5634, or even for applications where light dispersion is recommened, UR5635.

Achieving Consistent Performance and Design Requirements

LED Luminaires are frequently designed with a given colour temperature in mind, thus producing the wanted light output for each and every application. As briefly mentioned, the colour temperature within the LED are going to be suffering from the protection media applied and so the potential colour temperature shift ought to be tested in accordance with the LED used. Typically, a conformal coating, such as Electrolube AFA, has a small impact on these properties as a consequence of formulation within the material plus the very thin layer of 25-75