Abstract
We put forward a non-contact method for determining the transient two-dimensional (2D) temperature distribution of light emitting diodes (LEDs). A high-speed camera is employed to acquire the 2D reflective light of blue LED under test (468 nm) illuminated by a red LED (690 nm) as the incident light source to avoid the band-gap modulation effect. The 2D transient temperature distribution is derived in terms of temperature-dependent reflective light intensity relationship. Two cases are studied to test the system in this work under (1) 1980 fps frame rate with time resolution of 505 μs at 300 mA, and (2) 5600 fps with time resolution of 179 μs at 500 mA. Compared with the conventional infrared thermal imaging (TI) method, the spatial resolution and the time resolution of this proposed method increase up to one and two orders of magnitude, respectively.
Highlights
The GaN-based light emitting diodes (LEDs) have been widely applied in the lighting and display fields, including the general lighting and micro- or mini-LED displays [1]
The P-N junction temperature of GaN LED is a key parameter for evaluating the performance of GaN-based LED
Our research group has carried out several studies about measuring 2D surface temperature of GaN LED based on the hyperspectral imaging technology [7], [16]
Summary
The GaN-based light emitting diodes (LEDs) have been widely applied in the lighting and display fields, including the general lighting and micro- or mini-LED displays [1]. As a non-contact method, the thermal imaging (TI) camera can be used to detect the two-dimensional (2D) naked surface temperature of semiconductor device, but the spatial resolution is not eligible for micro-size device [4]. We put forward a non-contact method combing the high-speed camera and the reflective light intensity method (referred to as h-SCRLI hereafter) to detect the transient 2D temperature of LED under test (LUT). This solution owns merits of both high spatial resolution at submicron scale and high time resolution at the level of 100 μs, and is useful for the dynamic thermal detection of LED chips
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
