A LED Lifetime Acceleration Online Test System

Abstract

The invention discloses an accelerated on-line test system for the service life of an LED, and relates to an LED test system. The system comprises an aging device, a spectrum collection device, an electric test device, and a computer control processing module. The aging device is provided with a constant temperature controller and an aging constant current source. The spectrum collection device is provided with at least one optical path, a cosine collector, a testing sampling clamping tool, a sixteen-way optical multiplexer, and a spectrometer. The electric test device is provided with an electric matrix switch and a testing source meter. The computer control processing module comprises a computer control part and a computer processing part. A PID heater is employed for the direct temperature control of an LED heat sink, thereby not only enabling the system to achieve miniaturization and temperature control to be more accurate and stable, but also saving a large amount of energy. Moreover, the heater is provided with a thermal insulation device, thereby preventing high temperature from affecting testing equipment. An on-line testing result is more continuous, and an error caused by the inconsistence of testing conditions is avoided. Testing parameters are complete. The service life can be predicted more accurately in a short time through the combination of a physical model and a mathematic model.

Description

technical field [0001] The invention relates to an LED test system, in particular to an LED life-span accelerated online test system based on temperature and current as accelerated stress. Background technique [0002] As the fourth-generation lighting source, LED has many advantages such as energy saving, environmental protection, long life, high reliability, etc., and has been widely used in display screen backlighting, night scene lighting and other fields. However, the long life of LEDs (up to 100,000 hours) requires a lot of time, manpower and material resources in LED life and reliability testing. At present, the LED life test often adopts the method of life acceleration test, and accelerates the aging of LED by applying stress such as high current and high temperature. (J. Zhang, C. Liu, X. Chen, G. Cheng and A. X. Zhou, "Study on constant-step stress accelerated life tests in white organic light-emitting diodes", LUMINESCENCE, VOL.29, NO.7, 933-937 (2014 ); Zhao Mi...

AI Technical Summary

Problems solved by technology

A small number of devices that use online testing methods cause deviations in test results due to aging and inconsistent test status

[0006] 2. The high temperature box, constant current source, spectrometer, thermal resistance meter and other instruments need to be operated separately, which is not convenient for simultaneous control

[0007] 3. The high-temperature box has large volume, high power and high cost, resulting in a great waste of space and energy, and the high-temperature box is not specially designed for the aging system of LEDs. It does not take into account the particularity of the LED itself, and it is difficult to accurately test the LEDs temperature control

At the same time, the high temperature environment also has adverse effects on the probe and other test equipment, which is not conducive to the popularization and application of the system

[0008] 4. The junction temperature of the LED is an important parameter to reflect the life of the LED. The current life acceleration test system generally lacks junction temperature measurement and calculation

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