LEDs or Light Emitting Diodes are carving out a solid position for themselves in the automotive industry. Back in 2004, Audi first used LEDs for decorative purposes as daytime running lights in their cars. Nowadays, they are also used for functional purposes as a car’s primary lighting device. For car manufacturers such as SEAT, Volkswagen and Peugeot, LEDs are soon to be the new xenon headlamps. Let’s take a look at why car makers are opting for this technology over conventional systems and what that means for silicone applications.

 

LEDs are lighting up our cars

Current trends in car lighting systems focus on minimizing weight to save energy, and thus money, while maximizing safety and performance. Cars have evolved over the years to become more and more compact and lighting systems have also had to keep up with these advancements. As a result, LEDs are smaller in size, when compared to halogen or HID (High Intensity Discharge) lamps, and it is precisely this characteristic that appeals to car manufacturers as they can easily adapt LEDs to any assembly design.

In terms of safety, LEDs provide excellent visibility and reach their full lighting potential very quickly without any delays. Driving and braking maneuvers are thus safer as LEDs in headlamps and brake lamps light up instantaneously, providing other drivers with maximum reaction times.

Lastly, LEDs save you energy and costs. They do not use as much power as older lighting forms which means they do not heat up as much either. The more energy is saved, the less heat is emitted. Nonetheless, further efforts are still being made to improve their performance.

 

Transparency equals optimal LED shine

In order to protect them and increase their performance, LEDs are embedded into transparent silicone elastomer. Two techniques are employed to achieve this: encapsulation and potting. In the first process, silicone is used to encapsulate the electronic components of LEDs during the LED manufacturing process. In the past, polyurethane as well as epoxy have been used for this purpose but silicone has since replaced them. The second process known as secondary potting is a technique whereby silicone is used to encapsulate LEDs during their final installation in a lighting device. Potting with silicone protects LEDs from vibration, temperature and air and helps assembly with other electronic components.

Silicone is well suited for encapsulation and potting because of its crystal clear transparency. It protects while allowing maximum light to go through. Furthermore, it has non-yellowing properties and won’t lose transparency over time. It also exerts excellent adhesion to certain substrates such as semi-aromatic polyamides.

 

To the future and beyond with LEDs and silicone

Although LEDs may be gaining speed in the automotive industry, the number of LED applications for silicone is not necessarily following suit. Nowadays, the secondary potting process is not always needed when installing LEDs into Automotive lighting headlamps, which decreases the possibilities for silicone applications in LED lighting systems. In reality for Elkem Silicones, the use of LEDs in the automotive industry does not generate a greater number of applications for silicone because traditional lighting systems already use silicone much more than LEDs do. This is because traditional lighting generate higher temperature increase and needs to be waterproof and silicone ensures the integrity of these properties.

However, despite these reduced possibilities, silicone-based LED lighting can still benefit from the unique properties of silicone, especially its transparency.

 

Photo credits: Wikipedia commons

Yves Giraud

Posted by Yves Giraud

Global Business Manager Sealing & Bonding, Moldmaking, Sealants