How to choose and apply LED heat dissipation material?

- Aug 13, 2019-

As an alternative to halogen, incandescent and fluorescent lighting systems, the development of LED lighting market will be considerable. The growth of leds is due to their superior adaptability, longevity and efficiency over traditional forms of lighting. Leds have more freedom of design, provide a very long service life, and are highly efficient, converting most of the energy into light, thus minimizing the heat emitted.

Generate heat

However, leds still generate significant heat at semiconductor junctions. This heat can adversely affect leds, so cooling must be done to ensure the true advantage of solid state lighting (SSL). Leds are usually classified by color temperature, and there are many different color variations on the market.

If the working temperature of LED changes, its color temperature will also change.

Ease of thermal conductivity

There are many ways to improve the heat management of LED products. It is necessary to select the right type of heat conducting material to ensure the desired heat dissipation effect. In the field of materials, products range from heat-conducting encapsulating resin for heat dissipation and environmental protection to heat-conducting interface materials for improving heat conduction efficiency.

The heat-conducting interface material is a compound designed to fill the gap between the device and the radiator, thereby reducing the thermal resistance at the boundary between the two. The material accelerates heat loss and lowers the operating temperature of the equipment. Curing products can also be used as bonding materials.

Another option for heat conduction is to use heat-conducting encapsulated resins. These products are designed to provide protection to the equipment while allowing the heat generated within the equipment to escape into the surrounding environment. In this case, the encapsulated resin becomes a radiator and transfers heat from the device. These products can be used on LED devices and can also help to extract light from the cell depending on the color selected.

The encapsulating resin also includes the use of heat-conducting filler; However, the base resins, hardeners and other additives used can be changed to provide a wide range of options, including epoxy resins, polyurethane and silicone chemicals. Different chemical materials will provide a range of properties, each of which should take into account the ultimate application requirements.

Packaging material options

Epoxy resins are very robust and provide excellent protection in a wide range of harsh environments. They are rigid materials with low thermal expansion coefficient, and in some cases can be added to the product with a certain degree of flexibility. The addition of packaging resin can produce a large number of products with customized performance for various applications. Therefore, it is recommended to discuss the application in detail with relevant material suppliers.

Application properties

Regardless of the type of cooling product selected, there are some key attributes that must also be considered. These can be fairly simple parameters, such as the operating temperature of the equipment, electrical requirements, or other restrictions, such as viscosity, curing time, etc.

However, the most effective heat transfer may not be achieved by relying only on the value of bulk conductivity.

Therefore, lower interface thickness and higher thermal conductivity can maximize the improvement of heat transfer.