VLED Thermal Management
VLED CERAMIC PACKAGES ARE BONDED DIRECT ON METAL BODY BY EPOXY THERMAL ADHESIVE
The principles of thermal management are conduct heat away from the LEDs arrays and dissipate it into the surrounding air. This is the basics rule that all luminaries need to keep: As bigger dissipation as better.
The majority of LED failures on lamps are caused for high temperature caused by deficient thermal management. Elevated junction temperatures cause light output reduction and accelerated chip degradation.
Junction temperature is primarily affected by three parameters:
- Ambient temperature of the LED’s immediate surroundings
- Thermal path between the LED junction and ambient conditions
- Heat dissipated from the LEDs arrays by the metal body to the air
To achieve consistency and optimal performance of LED Light sources accurate thermal management design is necessary. Like all electronic components, LED’s have thermal and critical limitations. To keep optimal and long lifetime operation of the designed lamps is necessary keep temperature under junction temperature for the die of the LEDs by adequate and balanced metal body: As lower temperature as better.
Effective thermal management is essential to maximize the reliability and performance of LEDs arrays. If maximum operating temperature is exceeded, light output and lumen maintenance decreased and the useful life of the lamp are shorter.
VLED achieved an innovation on LED thermal management, bonded the ceramic arrays on the aluminum body of lamp by epoxy thermal adhesive with up to 30 W/MK of thermal dissipation that allow conduct heat away from the LEDs better than a conductive paste & metal screws.
VLED NOT USE SCREWS AND CONDUCTIVE PASTE ON ASSEMBLY AND PRODUCTION OF LAMPS
Ceramic substrates bring numerous benefits:
- + More reliable and longer-lasting than aluminum
- + Low coefficient of thermal expansion and contraction than aluminum
- + Plane surface maintained even at high temperatures, optimizing heat dissipation
- + Insulating properties of ceramics allows LED luminaries to pass various high voltage tests
- + Industry-leading hot lumen maintenance ratio up to 95% thanks to high thermal conductivity of ceramics
A ceramic substrate + engineering designed metal body ensure optimal heat dissipation and low thermal resistance for efficient thermal management that increased life of the lamp.
Deficient thermal management increase temperature operation and generate color drifts, forward voltage variations that decrease luminous intensity; these parameters will shorter lifetime of the lamps and generate low quality of white light.
Chip on Board on Ceramic Substrate
VLED develops an innovative Technology based on a semiconductor die mounted on ceramic substrate. This is an alternative to typical metal substrates, which have a thin dielectric layer that can be easily damaged, resulting on catastrophic LED failure. A metal substrate also enables drive voltages to reach the lamp heat-sink, which can create a risk of electric shock.
The ceramic surface provides optimal heat dissipation without discoloration. The effect is a low color shift with uniform lumen output and longer operational life at full performance. The design of VLED multi-chip LEDs arrays ensures effective heat dissipation as well as fail-proof operation. Even if individual dies fail, the entire array continues work properly. The matrix wiring lowers the thermal stress on the individual LED dies because the heat is dissipated evenly over the total area of the matrix. Moreover, the LED’s ceramic substrate ensures excellent heat dissipation and low thermal resistance for efficient thermal management.
Another advantage of VLED multi-chips is their flexibility. VLED mounts up to 170 dies closely together in a single array to create a homogeneous, ultra-compact light-emitting surface (LES), which can be linear, circular or square. One of the positive outcomes is enhanced flexibility design of all type of lamps as Street, tunnel, gas stations, Highbay, spotlights, down light, bulb, etc.
All VLED product dimensions (2525, 3838, 4008, and 4040 mm) ensure same size light-emitting surface; these LED arrays have identical emitting angles and are mechanically and optically compatible. As a result, they are suitable for a whole series of luminaires with different levels of brightness using same metal body, reflectors, lenses and housing shells that ensure lower inventory items and uniformity on family products.