LED thermal characteristic test method based on structure function

Abstract

The invention relates to a LED light source construction body and discloses a LED thermal characteristic test method based on a structure function. The method comprises the following steps that two groups of LED lamps with different packaging structures are selected, wherein packaging bodies and materials of the two groups of LED lamps are different; through using a characteristic of a linear relation which is formed by a LED U-I curve drifting under a small current situation and a PN joint temperature, a node voltage VF and a temperature TJ of the lamps driven by a constant current are recorded and a proportion coefficient S is calculated; when a transient cooling curve is measured, the two groups of LED lamps are placed at a 25-27 DEG C ambient temperature, a 350mA rated current is used to drive a sample for 10mins so that a heat stable state is reached, and then it begins to record a cooling curve during a transient test; a piece of paper is placed below the sample so that isolation performance is achieved, then different heat dissipation plates are used to record an obtained curve; according to the cooling curve, software is used to analyze and calculate a differential structure function Rth, and the structure of the tested LED lamps and an inflection point position in the curve are combined so that a thermal resistance K from a LED chip to a pin is obtained.

Description

technical field [0001] The invention relates to an LED light source structure, specifically, a method for testing LED thermal characteristics based on a structure function. Background technique [0002] LED is called the fourth-generation lighting source. It has the advantages of high luminous efficiency, energy saving and environmental protection, long life, and small size. It is widely used in indicator lights, signal lights, landscape lighting and other fields. However, as the input power of the LED increases, the temperature of the chip will increase, which will affect the parameters such as the luminous flux, color, and dominant wavelength of the LED, which will accelerate the aging process of the LED and cause premature failure. Especially for high-power LED devices, thermal characteristics will affect its operating temperature, life and luminous efficiency. Therefore, heat dissipation is one of the important bottlenecks for high-power LEDs to enter general lighting, ...

AI Technical Summary

Problems solved by technology

For example, the infrared imaging method is slow and limited by the spatial resolution; the electrical parameter method ignores the test of the optical power loss of the device, and there will be a large deviation when testing high-power LEDs

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