The continuous upgrading and improvement of LED explosion-proof lamp materials and packaging skills has promoted the continuous improvement of the brightness of LED explosion-proof lamp products. Different varieties of LED explosion-proof lamp backlight technology are more advantageous than traditional cold cathode tubes (CCFL) in terms of color, brightness, life, power consumption and environmental protection requirements, thus attracting active investment from the industry.
The power of the original single-chip LED explosion-proof lamp is not high, the heat generation is limited, and the heat problem is not big, so its packaging method is relatively simple. Pay attention to blasting cats. However, in recent years, with the continuous breakthrough of the material technology of LED explosion-proof lamps, the packaging technology of LED has also changed. The low-power LED of about 20mA has developed to the current high-power LED of about 1/3 to 1A. The input power of a single LED is as high as 1W or more, and even the packaging methods of 3W and 5W are more evolved.
Because the thermal problem derived from the high-brightness and high-power LED explosion-proof lamp system will be the key to affecting the performance of the product, to quickly discharge the heat of the LED components to the surrounding environment, it is necessary to start from the thermal management of the packaging level (L1&L2). The current practice in the industry is to connect the LED chip to a heat spreader with solder or thermal paste, and reduce the thermal impedance of the package module through the heat spreader. This is also the most common LED package module on the market. The main sources are Lumileds, LED world-renowned manufacturers such as OSRAM, CREE and Nicha.
Many terminal application products, such as mini projectors, automotive and lighting light sources, require more than a thousand lumens or tens of thousands of lumens in a specific area, and a single-chip package module alone is not enough. Perfunctory, to multi-chip LED packaging, and the chip directly attached to the substrate is the future development trend.
The problem of heat dissipation is the main obstacle to the development of LED explosion-proof lamps as lighting objects. The use of ceramics or heat pipes is an effective way to avoid overheating, but heat dissipation management solutions increase the cost of materials. The purpose of high-power LED heat dissipation management planning is to have Rjunction-to-case is one of the materials-based solutions to reduce the thermal resistance between heat dissipation from the chip and the final product, providing low thermal resistance but high conductivity, allowing heat to be transferred directly from the chip through die attach or thermal metal methods to the outside of the encapsulation case.
Of course, LED heat dissipation components are similar to CPU heat dissipation. They are mainly air-cooled modules composed of heat sinks, heat pipes, fans and thermal interface materials. Of course, water cooling is also one of the thermal countermeasures. For the most popular large-scale LEDTV backlight modules at the time, the input power of the 40-inch and 46-inch LED backlights was 470W and 550W respectively. From the perspective of 80% of them being converted into heat, the required heat dissipation The amount is about 360W and 440W.
So how to take this heat away? At present, the industry has water cooling methods for cooling, but there are concerns about high unit price and reliability; heat pipes, heat sinks and fans are also used for cooling, such as the 46-inch LED backlight of SONY, a Japanese manufacturer. source LCD TV, but the problem of fan power consumption and noise still exists. Therefore, how to design a fanless cooling method may be an important key to determining who will win in the future.