应用案例

Application Of FOTRIC Thermal Camera In LED Power Chip Temperature Detection

2019-06-04

Overview Of LED Power Chip

LED has been extensively applied with long service life and high luminous efficiency. The key to technology upgrade is how to develop more efficient and stable LED chips with regard to both high-power LED chips oriented to accent lighting and overall illumination, and low-power LED chips applied to decorative illumination and simple auxiliary lighting.

Should LED have quality problems, it will create a lot of heat while in service, and especially, high-power LED has significant heat effect. If the heat cannot dissipate timely, the temperature of p-n junction (junction temperature) in LED will rise rapidly and therefore cause the reduction in effective recombination, probability of chip carriers and resin case aging leading light decay, thus significantly affecting the service life of LED.

The predicted service life of LED light source exceeds 50,000 hours at present, which is the theoretical service life of LED light source working at 25℃. The severe environment like high temperature and high humidity exists in actual use of LED light source, which will magnify the defects of LED light source, accelerate material aging and thus speed up the failure of LED light source. For example, if the junction temperature of a lamp bead rises from 115℃ to 135℃, the service life will decrease by 3/5, so the heating and heat dissipation of LED become the major issues of the development of LED lighting technology.

 

What Problems Need To Be Solve By Customers?

An optoelectronics technology company is dedicated to R&D and production of LED chip, light emitting diode, LED light source module, LED transmitting tube and LED semiconductor lighting products and mainly manufactures internationally advanced 4-inch wafer and 120 lumen/watt LED power type chip.

It needs to observe the internal temperature distribution and uniformity inside the LED power chip. The temperature of metal chips in LED shall stay the same while the temperature of non-metal parts shall keep the same when LED is working. It needs to detect real-time temperature variation in LED power chip.

 

Current Solutions And Their Disadvantages

  • The size of LED chip is very small with 1mm*1mm, and the temperature distribution needs to be measured. Under normal conditions, chip internal structure can be observed under 20-times microscope, so it is difficult to measure it by a traditional way.
  • The temperature gun reading is inaccurate because of the too small size of LED chip.
  • The chip is too small to use contact temperature measurement with the thermocouple since the thermocouple cannot be installed.
  • Hand-held thermal imager is easy to shake and therefore cannot ensure precise thermal imaging temperature measurement.
  • The thermocouple at the front end of data collector cannot be installed, so it is unable to measure the temperature variation continuously.

 

How To Help Customers To Solve The Problems By Use Of FOTRIC Product And Its Advantages?

The figure below involves in a real testing of a LED power chip that is sized 1mm*1mm, and the customer desires to observe the temperature distribution on the chip surface after LED is powered on. The six yellow dots show the temperature of metal chip which shall be kept the same and the white dots indicate the temperature of non-metal parts which shall be kept the same too.

 

Advantages Of FOTRIC Infrared Thermal Camera:

  • The temperature distribution of LED chip can be read through non-contact mode, avoiding the temperature variation caused by contact temperature measurement.
  • If equipped with macro-lens, FOTRIC thermal imager can observe very small objects.
  • FOTRIC thermal imager is equipped with R&D test platform and allows long-term temperature measuring, thus ensuring a more accurate measurement.
  • FOTRIC thermal imager is designed with bypass power supply and therefore is capable of long-term on-line monitoring;
  • The fully-radiometric thermal video allows the viewing of temperature change history and any further analysis.

 

Precautions And Product Configuration Options 

Fotric 226 is recommended and the bundle contains a 50μm macro-lens and a R&D test platform. Or Fotric 227/228 equipped with a50μm macro-lens may be used. Fotric 227/228 equipped with a 20μm macro-lens is required if customer want to test an even smaller chip.

 

Other Customers Need To Solve Such Problems

  • R&D and manufacturing enterprises of LED chip, light emitting diode, LED light source module, LED transmitting tube and LED semiconductor lighting products
  • Upstream and downstream testing companies of LED semiconductor lighting products
  • Other chip manufacturers