THE LED FILAMENT
or the LED filament
WHAT IS AN LED FILAMENT AND HOW DOES IT WORK
An LED filament refers to an LED filament onto which individual diodes are mounted using COB (Chip On Board) technology. The substrate material for these diodes is, for example, sapphire glass (transparent), ceramic or copper. These materials have inherently good thermal conductivity properties and offer a certain degree of cooling capacity.
A broad light spectrum is produced by bonding diodes of different colors to the substrate. Additionally, they are coated with a fluorescent layer. This layer forms the yellow outer sheath of the filament, which is clearly visible to the human eye. Depending on the composition of the fluorescent material and the arrangement of the diodes, various colors of light can be produced. SEGULA LED filaments are completely encased in the fluorescent coating. This results in a wide beam angle, meaning almost omnidirectional light emission. If the filaments are coated on one side only, the beam angle and the lumen output are naturally reduced. This is, of course, more cost-effective, but it also reduces the quality of the light.
SMD technology
To achieve the visual effect of a string of lights, the individual LEDs are mounted and connected in series, unlike in SMD technology. There is an electrical contact at both ends of the string to allow the voltage to be applied.
Hard LED filament with a fluorescent coating
Another component found in ALL LED light sources is a small, usually invisible power supply unit built into the base. This converts the alternating current from the mains supply into the direct current required to operate LED light sources.
In SEGULA light sources, we also use a small capacitor which bridges the troughs of the emitted light. This allows us to reduce so-called ‘flickering’ to a minimum.
COOLING
Thermally conductive gases are filled into the glass bulbs, as these ensure consistent cooling of the filaments. Constant cooling guarantees a long service life and, for the most part, consistent luminous intensity. The heat-sensitive semiconductor crystals of the LED are thus kept under constant cooling and achieve a very long service life.
To achieve a maximum lumen output of up to 4000 lumens, we at SEGULA use the ceramic filament (COC – Chip On Ceramic). This material is ideal as it has excellent thermal conductivity and allows relatively large diodes to be mounted. The SEGULA Bright Line is equipped with this technology.
FURTHER DEVELOPMENT – SOFT LED FILAMENT
In 2017, the world-first ‘Soft Filament’ was launched on the market for LED light sources, enabling us to almost replicate the appearance of incandescent bulbs. Flexible materials replace rigid substrates such as ceramic or sapphire glass. The so-called “Blue Diamond” silicone-based polyester film is highly flexible and allows for curves down to a minimum diameter of approx. 10 mm. There are therefore virtually no limits to the shaping of the filaments, and the appearance now truly resembles the classic tungsten filament we all know. Until 2017, this filament was used only in bulb lamps to ensure constant cooling through gas circulation.
WORLD FIRST – SOFT FILAMENT "PLUS"
The revolution is just around the corner! The Soft Filament “PLUS”. In this technical innovation, the heat sinks are positioned directly against the LED filament and dissipate heat away from the diodes. They look like tiny wings on either side of the LED filament. This means we are no longer reliant on glass bulbs and cooling gases. Completely new styles and designs are suddenly possible and are being realised at SEGULA, for example in the Art Line!
Another positive side effect of this technology: a significantly higher lumen output is possible, thanks to the improved and more consistent cooling directly at the filament.
Naturally, we use the Soft Filament “PLUS” not only in our open-design range but also within our other series. We also utilise its positive properties in many other light sources. In the elegantly shaped bulb lamps of the Soft Line, this innovative filament reveals its full potential!
