Encapsulating LED drivers with a flame-retardant plastic

LED technology has developed rapidly in recent years and is increasingly used in various applications such as household lighting, automotive industry and public facilities. An important aspect in the production of LED drivers is to ensure the safety and durability of the devices. Here, encapsulation with flame-retardant plastics plays a central role. In this article, we will explain in detail the challenges, requirements and solutions for encapsulating LED drivers.

Challenge for the customer

Flame-retardant plastics are critical to safety in electronics because they act as a fail-safe in the event of a fire. These materials are not completely flame-retardant, but are self-extinguishing, meaning they stop the flames from forming once the ignition source is removed. This prevents the fire from spreading and protects the electronic components.

An important standard for certifying flame-retardant materials is the UL94 vertical burn test, which is widely used in electronics manufacturing. The test evaluates how well a material can resist flames and extinguish itself. Materials that pass this test receive a rating such as UL94 V-0, which is the highest level of safety.

Industries with high demands on flame-retardant materials

Some industries are particularly dependent on flame-retardant materials. These include:

• electric vehicles: Batteries in electric vehicles require special flame-retardant materials to prevent the spread of fire in the event of a defect or accident.
• LED lighting: LED drivers and other electronic components in lighting systems must be flame retardant to ensure the safety of the installation.

Specific challenge

The specific challenge for the customer was to find a cost-effective encapsulation product with a UL94 V-0 rating for use in LED driver transformers. The material also had to have a flowable viscosity so that it could be applied using automated equipment, which is important to ensure efficient and consistent production.

Key customer requirements

To successfully overcome the challenges, several specific requirements had to be met:

UL94 V-0 certification

The most important requirement was UL94 V-0 certification. This rating ensures that the material has passed the most stringent fire safety tests and is self-extinguishing in the event of a fire. This is especially important in applications where the safety of electronic components is of the highest priority.

Temperature resistance

The material had to withstand temperatures of up to 100°C. LED drivers and other electronic components can reach high temperatures during operation, so it is important that the encapsulation material remains stable and retains its protective properties even under these conditions.

Automated dosing

Another critical point was that the material could be dispensed using automated equipment. This requires a certain fluidity of the material so that it can be applied precisely and efficiently. Automated dispensing systems improve production speed and consistency while reducing manual effort and the potential for error.

Solution: MG Chemicals 834HTC

MG Chemicals 834HTC epoxy encapsulant was selected to meet these requirements. This 2-part encapsulant cures to a rigid surface and offers high thermal conductivity. Most notably, it achieves a UL94 V-0 rating, making it an excellent choice for applications where fire protection is critical.

Properties of 834HTC Epoxy

• High thermal conductivity: This helps to effectively dissipate heat from the electronic components and extend their lifespan.
• UL94 V-0 rating: This certification confirms that the material meets the highest standards in fire protection.
• Non-abrasive fillers: This property makes the material particularly suitable for use with customized dispensing equipment as it does not damage or wear the equipment.

Collaboration for optimal results

An optimal solution was developed in collaboration with a third-party specialist dispensing equipment company. This collaboration ensured that no air pockets were created during the mixing process that could affect the performance of the cured system. By avoiding air pockets, the integrity and reliability of the potting material is further improved.

Conclusion

Modern luminaire designs, and LED drivers in particular, require the use of flame-retardant plastics to prevent uncontrolled fires and ensure equipment safety. Potting with a flame-retardant resin such as MG Chemicals 834HTC offers a simple and effective solution. Not only does this material meet stringent UL94 V-0 standards, but it is also easily applied using specialized equipment, allowing for easy scaling of production.

Using MG Chemicals 834HTC increases the safety and reliability of LED drivers by minimizing potential fire risks and meeting customers' stringent requirements. This solution ensures that electronic components are protected from overheating and fire hazards while keeping production processes efficient and consistent.