LED and LED backlight heat sink
Continue to improve the brightness of the LED products LED material and packaging technologies continue to evolve, prompting increasingly wide application of LED to LED as the backlight of the display, the more recent hot topic, mainly different types of LED backlight technology , respectively, than in the color, brightness, life, low power consumption, degree and environmental demands such as the traditional cold cathode fluorescent lamp (CCFL) advantages, thus actively involved in attracting industry.
First single-chip LED power high calorific value, heat is not a big problem, so the package is relatively simple. But in recent years, with the LED materials technology breakthrough LED packaging technology also will be changed gradually developed into a flattened shells package from early single-chip, large-area multi-chip package module; their operating current by the early 20mA around the low-power LED progress to about 1/3 to 1A of current high-power LED, single LED input power up to 1W even to 3W, 5W package evolution.
Due to the high brightness and high power LED system derived from the thermal problems will affect the product features pros and cons to LED components heat quickly discharged to the surrounding environment, we must first begin from the thermal management of the package level (L1 & L2). Current industry practice the LED chip solder or thermal paste after soaking piece, via a heat spreader lower module thermal impedance of the package, which is currently the most common available LED package module, main source of Lumileds OSRAM, Cree and Nicha LED internationally renowned manufacturers.
Terminal application products, such as mini-projector, automotive and lighting lamp source, the required amount of lumens in a particular area need more than thousands of lumens or thousands of lumens, rely on a single chip package module clearly insufficient to meet directly toward multi-chip LED package, and chip adhesion substrate future trends.
The heat problem is a major obstacle for the illumination of objects in the LED development, the use of a ceramic or heat pipe effectively prevent the overheating of the method, thermal management solutions to the rising costs of materials, high power LED thermal management design to effectively reduce the thermal resistance between the chip cooling to the final product, R junction-to-case is one using a solution of the material, providing a low thermal resistance high conductivity, the method of adhesion or hot metal through the chip to the heat transmitted directly from the chip to the Encapsulates the outside of the housing.
Of course, LED cooling components and CPU cooling similar, are composed of air-cooled heat sink, heat pipe, fan and thermal interface materials module-based, of course, water-cooled heat countermeasures one. The most popular large-size LED TV backlight module, 40-inch and 46-inch LED backlight input power of 470W and 550W, 80% turn into a hot look, the required heat about in 360W and 440W.
So how will this heat go? Industry useful water-cooled cooling, but the high price and reliability concerns; useful heat pipe with the heat sink and fan for cooling, say Japanese manufacturers SONY 46-inch LED-backlit source LCD TV, but the fan power consumption and noise problems still exist. Therefore, how to design a fanless cooling, may be the key to decide who can win.
[Launch Time: 2013-03-20 22:23:33]