标签：heat sink

led solution and heat sink

Analysis of the reasons for the rise of led lighting lighting source temperature.

Limiting factors currently limit the development of led lighting in addition to the cost, is the heat. The LED is a semiconductor light emitting device, with the change of its own temperature. Its characteristics change dramatically. Led the higher the temperature, the light source the sooner the light fades, the shorter the life. Led normal use standard terms of light decline to 70%, when the junction temperature of 65 ° C, led life more up to 90,000 hours to 100,000 hours; the junction temperature rose to 75 ° C, life expectancy dropped to 50,000 hours life of 20,000 hours; junction temperature of 95 ° C, the light source life; When the junction temperature of 105 ° C, more than ten thousand hours led solution. In view of this, the key to extend the led light source life is to reduce junction temperature to accelerate the cooling effect of the led lighting.

led solution and heat sink

led in the power drive. Not only produce light energy, but also generate a lot of heat. For the LED chip is smaller, its own thermal capacity is also small, the heat generated can not be conduction out in a timely manner, and therefore will produce a high junction temperature. LED illumination light source, in addition to as the visible light energy consumed, the other energy are converted into heat, about 70% of the electrical energy into heat energy. Further, since the the led package small area, less cooling by convection and radiation, and also to make the led light led solution source to the accumulation of a large amount of heat, so that the rise of the temperature of the LED lights source.

led lighting on the hazards of heat bad
Electronic components deformation
led lamps by a number of electronic components. The coefficient of thermal expansion of each component of the material is not the same. When the temperature rises, the expansion ratio of the combined elements is not the same, can lead to the material bending deformation occurs even at the connection, because the stress is too large cracks.

Electronic components blown
LED semiconductor element as a heat source when the temperature l, its impedance becomes small, increase in current, thermal energy increases, the temperature rises, so the cycle of the vicious cycle, prone electronic components blown circuit fault.

Accelerated aging encapsulation material
LED chip packaging use of the epoxy resin, is easily oxidized when the temperature rises, aging and embrittlement, such that its light transmittance decreased, thereby causing led out of the light quantity decrease. The higher the temperature, this phenomenon becomes. After repeated at high temperatures led solution. Material multiple expansion and shrink, will reduce the strength of the material, thereby undermining the performance of the material failure affect their life.

smd led heat sink

Traditional thermal conductive material for metals and metal oxides, as well as other non-metallic material, such as graphite, carbon black, A1N, SiC, etc.. With the development of science and technology and the production of many products of the thermal conductivity of the material put forward higher requirements, has excellent overall performance, light weight, chemical resistance, and excellent electrical insulating properties, impact resistance, and easy processing molding . The thermal conductivity of insulating polymer composite materials because of their excellent overall performance is more and more widely used smd led.

However, due to the polymer material is more than a poor conductor of heat, limiting its application in thermal conductivity, and thus the development of new polymer materials with good thermal conductivity, become an important development direction of the thermal conductivity of the material now. Especially in recent years, with the rapid development of high-power electronics, electrical products, is bound to appear more and more heating products, leading to product efficacy to reduce life shortening. Some data indicate that the electronic components temperature is increased by 2 ℃, its decreased reliability 10%; 50 ° C when the life expectancy is only 25 ° C when the 1/6.

smd led heat sink

The heat conductive filler is mainly divided into two: one is a thermal insulating filler, such as a metal oxide filler, a metal nitride filler. Another is the thermal conductivity of non-insulating filler, such as carbon-based filler, and various metal filler and the like. The former is mainly used for electronic components encapsulated materials electrical insulation performance requirements of the occasion, the latter mainly used in chemical equipment, heat exchangers lower electrical insulation performance requirements of the occasion. The type of filler, the particle size and distribution, the filling amount and the filler and matrix interface between the performance of the thermal conductivity of the composite material has an impact smd led.

The thermally conductive plastic using the matrix polymer: PA (nylon), the FEP (perfluoro polypropylene), PPS, PP, PI epoxy resin, POM, PS and PS and PE composite material or the like.

The current domestic and international power LED Flood Light industry lamps commonly used aluminum as a heat sink material of the shell, using thermal plastic shell can save a lot of energy and improve production efficiency, reduce the cost of LED products have a very real economic significance. Use plastic could greatly expand the lighting engineers to develop products Ling and creativity, more lightweight design beautiful products for faster promotion to the mass consumer. Based on the basis of extensive research, we propose to use cooling plastic mold production 8 watts, whether the temperature of the various parts of the 10-watt LED downlight base, check product conform to the requirements for eligibility to test heat plastic for mass production smd led.

t8 led fluorescent tube and heat sink

With global energy shortage and environmental pollution, the LED with its energy-saving and environmental features of the vast space, the application of LED light products are attracting the world’s attention in the lighting field. In general, the LED lights work stability,  no matter the quality is good or bad, and the lamp cooling is essential, the heat of the high brightness LED lamps (t8 led fluorescent tube) on the market, often using the natural cooling effect, which is not satisfactory. LED lamps, LED light source to create LEDs, thermal structure, drives, lens, so the heat is also an important part, if the LED can not be a good heat, it’s life will also be affected.

1, thermal management is the main problem in the high-brightness LED applications
P-type doping of III-nitride limited by the solubility of the Lord and hole higher than that of Mg activation energy and heat are particularly vulnerable in the p-type region; Sapphire substrates is extremely low thermal conductivity of the device thermal resistance increase, resulting in severe self-heating effect, have a devastating impact on device performance and reliability.

t8 led fluorescent tube and heat sink

2, the heat of high-brightness LED
Heat concentrated in a small size chip, the chip temperature rises, causing non-uniform distribution of heat stress, decline in the luminous efficiency and the lasing efficiency of the phosphor; the device failure rate increased exponentially when the temperature exceeds a certain value. The statistics show that the component temperature rise of 2 ° C, reliability decreased by 10%. When multiple LEDs (t8 led fluorescent tube) are densely packed composition of white light illumination system, the heat dissipation problem is more serious. Solve the problem of thermal management has become a prerequisite for high-brightness LED Street Light applications.

3, the chip size and the cooling of relations
The most direct way to improve the brightness of power LED (t8 led fluorescent tube) is to increase the input power is bound to increase the input power in order to prevent saturation of the active layer must increase the size of the pn junction. Single-tube power increases depends on the device the ability to export heat from the pn junction to maintain the existing chip material, structure, packaging technology, the current density on the chip the same and equivalent thermal conditions, a separate increase the size of the chip junction area The temperature will continue to rise.