Most used technology for LED Products
is mainly made by LED Chip, LED Driver, Heat sink,aluminum PCB，Thermal Paste etc. Elite LED High bay light should have a lifespan and electrical efficiency that is several times better than traditional HID High bay light. But in fact, customers always complains about the LED high bay light’s quality when they buy from China. We have heard many stories like” the use Meanwell and Bridgelux LED Chip, but the lamp start to fail after 1 year or 2 years”, so what make the LED high bay quality so different even you buy it with brand driver and brand LED Chips.
We need to know how we design LED High bay to understand why. But before that, we need to know different technical of different LED High bay components.
Part I : LED Chips
How to know the LED Chip is good or not good?
The LED marketplace is often referred to as “The Wild Wild West”. The market seems to be ruleless as many manufacturers released the LED Chips may or may not live up to their stated performance and lifetime claims. LM-80 is a law to control these manufacturers.
LM-80 refers to a method for measuring the lumen depreciation of solid-state lighting sources, such as LED packages, modules and arrays. Before the advent of LM-80, LED component manufacturers each reported lumen maintenance data using their own disparate and varied systems. To avoid customer confusion, members of the Illuminating Engineering Society (IES), including members from Philips Lumileds, came together to create a standard methodology that would allow customers to evaluate and compare the lumen maintenance of LED components from different companies. LM-80 was born.
LM-80 can be a useful tool for lighting professionals who are looking to analyze LED High Bay Light; however, it is not a measure of LED High Bay Light performance or reliability. It only describes how to measure how one part of an LED High Bay Light—the LED light source—performs over a period of time and under certain set conditions. Other components, including the LED optical system, heat sink, LED drivers and Heat Sink, should also be taken into consideration to form a full picture of an LED High Bay Light’s projected useable life.
This fixture shows the samples tested result from Nicha NF2L757DR, The LED chip is tested under 85 degrees and powered with 100mA, after 10,000hours, the Lumen maintenance is still around 96.5%. So technically, if we can make a LED High bay light, with 100mA powered to the Nichia LED Chip, the temperature of the Aluminum PCB is below 80 degrees when the light is continuely lighted for more than 4 hours, the Lumen Maintenance is above than 96.5% after 10,000 working hours, which means 8 hours lighting time per day, 1250 days.
After Comparing and choosing, we decide to use Nicha LED Chip, with 3000K, 4000K,and 5500K.
With LM80, we can develop LED high bay light which meet the market requirement faster than before, and Help customer to have a image of the life time on the LED high bay Light. But, this is just a start.
Part II : PCB Technologies
PCB technologies commonly used for LED High bay Lights, here we only show 2 maintypes PCB.
– Thick copper PCB
Thick Copper PCB are PCBs with copper layer thicknesses of 105 µm to 400 µm, and up to 500 µm in special cases. According to requirements and technology used, layers are applied in a planar way as external and/or internal layer. The basis material used is FR4 or a metal substrate (Al, Cu) with a dielectric. The primary application sector consists of applications with high power (high current) and for the cooling of components with large thermal power losses. Constructions are mainly multi-layer or double-sided PCBs. A special form is the so-called “iceberg” technology. Here a thin-layer copper layout is combined with selectively applied thick copper layers. The thick layer areas are recessed into the basis material (FR4) to achieve a uniform surface level.
Expanding the copper cross-section achieves significantly wider heat dissipation as well as enabling local thermal build-up to be controlled.
We can see some manufacturer use this PCB to produce LED High Bay Light, this should be a good solution to heat radiation, but This is not all, bad heat sink design and no good quality Thermal Grease used, make this kind product to be more expensive than the LED High Bay manufactured with Aluminum PCB, and when the lamp is well designed, we do not need this expensive PCB to match the quality requirement from LM80 or LM79.
– Aluminum with thin insulation layer
The core of the PCB here is a ceramic carrier substrate to which the conductors are directly applied via thick film or thin film technology. According to the specific variant, ceramic carriers have thicknesses of 0.25 mm to 3 mm. Because ceramic substrates themselves are electrically insulating but are thermally conductive, heat can be dissipated directly without other thermal barriers.
Aluminum oxide and aluminum nitride are usually used as substrate materials, the latter having significantly superior thermal conductivity properties. The thermal conductivity of aluminum oxide is in the range of ~ 20 – 25 Wm-1K-1 , and that of aluminum nitride is at (~ 170 Wm-1K-1). Another advantage among many is low thermal expansion. In combination with ceramic-based High-Power LEDs, they are thus primarily suitable for applications with high thermal cyclic loads.
We can see this is the most widely used PCB for almost all LED lamps, from LED Street Light, LED High bay lamps to LED Spot light, the prices different for aluminum PCB is very wide , the quality difference is very wide too .
Part III: Thermal Housing
The most common heat sink materials are aluminium alloys. Aluminium alloy 1050A has one of the higher thermal conductivity values at 229 W/m•K ,but is mechanically soft. Aluminium alloys 6061 and 6063 are commonly used, with thermal conductivity values of 166 and 201 W/m•K, respectively. The values depend on the temper of the alloy.
A heat sink transfers thermal energy from a higher temperature device to a lower temperature fluid medium. The fluid medium is frequently air.In thermodynamics a heat sink is a heat reservior that can absorb an arbitrary amount of heat without significantly changing temperature. Practical heat sinks for electronic devices must have a temperature higher than the surroundings to transfer heat by convection, radiation, and conduction. The power supplies of electronics are not 100% efficient, so extra heat is produced that may be detrimental to the function of the device. As such, a heat sink is included in the design to disperse heat to improve effcient energy use.
After carefully design and test, Elite™ LED High Bay light reach a amazing effect on thermal dissipation, please see picture below.The max temperature is only 58.2 degrees. This is a remarkable result on thermal housing design.
Part IV: LED Driver
Meanwell driver is a world famous LED Driver brand, who have stable quality, and most of the drivers are with 5 years warranty.
We use the HBG-160 for our 150Watts LED high Bay lamp. HBG LED driver is specialize designed for LED High bay lights, which is IP67 Rated, PF>95%, Driver efficiency up tp 93% which is very high for 150Watts.
beside the Power driver, we can supply Elite™ LED High Bay light with DALI and Zigbee control.