Improved LED thermal performance

Solve the heat problem is the fundamental package approach

Temperature solution to the problem is to reduce the package thermal resistance; to maintain the survival of life LED's use of the approach is to improve chip shape, that the use of appropriate small-scale chip; improve the LED flash rate by improving the chip structure that fit using small-scale chip; The average flash of the special nature of the approach is to improve the LED package approach, these two approaches have been developed in succession. Because the ring oxygen of natural resin reference wavelength of 400 ~ 450nm light percentage of 45%, silicon less than a hundred percent packaging materials, luminance half time ring oxygen less than one million hours of natural resins, silicon packaging materials extended to 40,000 hours or so, almost by default with the lighting of the same length of survival, which means that the period without the use of lighting facilities Gaiyi white LED. However, ownership of natural resin of high elasticity silicon soft materials, processing essential for the use of natural resin will not scratch the surface of the silicon manufacturing technology, the addition of natural resin processing highly dependent Fenxie silica, essential for the future because of this R & D can improve the appearance of a special nature of the technology.

Related to the longevity of LED, LED manufacturers until now resorted to changing the packaging material, while the fluorescent materials within the spread in the packaging materials, packaging materials, especially silicon than the traditional blue and near ultraviolet LED chip above the ring oxygen of natural resins packaging material, the material can be more effective constraints reduce the rate of deterioration and the speed of light pierced.

Change the constraints of material degradation and packaging materials to reduce the rate of the speed of light pierced

Toshiba Lighting ago in 2003, 400mm square aluminum appearance, flash repair shop rate of 60lm / W low thermal impedance white LED, no cooling fan and other cooling components in particular premise, try making the light beam to 300lm LED plate. Main terminus of the current density of more than 2 times increase, the Bu Wei could not help but easy to extract light from the large chip, the final outcome will result in hand, the rate is not as low-power flash white LED dilemma. Based on the German OSRAM Opto Semi conductors Gmb end of the experiment results show that the above mentioned structure of the LED chip to the welding point of the thermal impedance can reduce the 9K / W, is about a traditional LED 1 / 6, after the LED package to give to 2W electricity, LED chips with high temperature than the welding point of 18K, even if the printed circuit board temperature rise rose 50 ℃, with the temperature at most only about 70 ℃; contrast the past to reduce the thermal resistance, then once, LED chip with temperature will be subject to the printed circuit board temperature. White LED temperature rise restricting the use of cooling can be considered a suitable printed circuit board LED package approach, the main terminus of the natural resin encapsulated under high temperature conditions, coupled with the rapid deterioration of light mapping, follow the laws of Porto Vilnius 10 ℃ lower temperature survival The period will be extended two times China Association of Lighting LED Lighting portal.

Because the heat sink and printed circuit board between the precision of detail about the direct thermal effect, because the pre-printed circuit board becomes very complicated.

To reduce the thermal resistance, many LED manufacturers overseas, the LED chip set porcelain ceramic material made of copper and the cooling device (heat sink) looks to continue and then welding the form of printed circuit board to the use of heat with a wire cooling fan petition forced air-cooled cooling device. Toshiba Lighting because of trying to obtain Haobo making experience, because this expression because the company mimic the analysis of technological advances to improve in 2006 after more than this 60lm / W white LED, you can easily use lighting, frame thermal conductivity increase or use the form of pre-cooling fan to force air-cooled heat lighting, special cooling technology without the plate structure can also use white LED.

Lumileds in 2005 with the production of high-power LED chips, combined with the allowable temperature as high as +185 ℃, higher than other companies its class 60 ℃, the use of traditional RF 4 printed circuit board package, surrounded by the background temperature is within 40 ℃ input current equal to 1.5W of power (about 400mA). This is LED manufacturers should consider appropriate use of porcelain as the Ordovician and metal packaging materials, the main terminus of the Department. Even packaging technology to allow high-calorie, but the combination of LED chip temperature might exceed the allowable value, the industry finally has realized the ultimate package to solve the heat problem is the fundamental way.

LED package structure of three main cooling

LED light source package thermal problem has been encountered in the development of LED products is very important, especially thermal material selection, has been the engineer's problem. Because the product on the thermal conductivity of materials is very critical.

For now, the thermal conductivity of ceramic materials is a very good material, it has a high thermal conductivity, good volume performance (no, no shrinkage, deformation), good insulation and thermal conductivity. Therefore, the use of ceramic materials will be the next major trend in the development of LED products!