High operating temperatures have a variety of effects on LED light lifespans, and they frequently result in a notable decrease in lifespan. The primary effects and their causes are as follows:
1. Faster light decay, or a reduction in brightness
Increase in junction temperature: The semiconductor chip (PN junction), which forms the core of an LED, will directly raise its junction temperature in response to high temperatures. The LED's light decay rate may increase by 1.5–2 times for every 10 °C increase in junction temperature, which would cause the brightness to drop more quickly.
Degradation of fluorescent powder: White LEDs use fluorescent powder to turn blue light into white light. High temperatures can cause fluorescent powders to age, losing their luminous efficiency and color temperature stability and perhaps resulting in color shift.
2. Reduce the longevity of electronic parts
Damaged driving circuit: The LED power supply's electrolytic capacitors, resistors, and other parts are temperature-sensitive. High temperatures can hasten the electrolyte's evaporation (a 10 °C increase in temperature can cut capacitor lifespan in half), which can cause the driving circuit to fail and ultimately harm the LED light as a whole.
Degradation of semiconductor materials: Elevated temperatures can increase leakage current, decrease luminous efficiency, and worsen electron migration and defect formation inside LED chips.
3. Physical harm brought on by heat stress
Variations in the growth of materials: The coefficients of thermal expansion of the various materials used in LED packaging, such as silicone, ceramics, and metal substrates, vary. Extended exposure to high temperatures can lead to open circuit problems by causing solder joint cracking, gold wire breaking, or interface separation.
Packaging material aging: Packaging materials made of silicone or epoxy resin are susceptible to yellowing and hardening at high temperatures, which affects heat dissipation and reduces light transmission.
4. Reduced effectiveness and higher energy usage
Reduced efficiency of photoelectric conversion: A vicious loop of "high temperature → low efficiency → higher temperature" results from the quantum efficiency of LEDs decreasing at high temperatures and more electrical energy being transformed into heat instead of light energy.
Risk of thermal runaway: Thermal runaway, which can quickly and totally destroy LED chips, can be brought on by extremely high temperatures.
A Quantitative Impact Example
The connection between longevity and temperature: An LED's theoretical lifespan, which is often determined by how long it takes for light to fade to 70% of its original brightness, may be lowered from 50,000 hours to roughly 25,000 hours if its junction temperature increases from 85 to 95 degrees Celsius (exact numbers vary depending on design and materials).
The model of Arrhenius: This model, according to which the chemical reaction rate (aging rate) doubles for every 10 to 15 degrees Celsius increase in temperature, is frequently used to describe the lifespan of electronic components.
How may the effects of high temperatures be mitigated?
Improve the design of heat dissipation: Make sure the junction temperature is below the specified limit, which is typically ≤ 85 °C, by using heat dissipation fins, heat pipes, or aluminum substrate.
Regulate the temperature of the surroundings: LED lighting fixtures shouldn't be used in enclosed spaces or areas with high temperatures, like those adjacent to ovens.
A reasonable driving current To lessen heat generation, avoid overloading and lower current (but balance brightness).
Choose materials that can withstand high temperatures, such as anti-aging phosphor, ceramic packing, or silicone grease with high thermal conductivity.
User safety measures
Put in ventilation: To prevent heat buildup, make sure there is air circulation around the lighting fixtures.
Frequent cleaning Heat dissipation can be impeded by dust formation, particularly for outdoor or industrial lighting installations.
Avoid operating at full load all the time: Using it sparingly or dimly can prolong its life.
excessive heat is the "invisible killer" of LED lights, and effective thermal control is essential to extending their life, so we should take measures to avoid High operating temperatures for LED Lights , you can check on our website http://www.benweilight.com
