Methodology for the Inline Die Attach Characterization of Power LEDs

Qualification of the die attach quality is a very important issue in case of Light Emitting Diodes (LEDs), as the operating temperature of these devices is usually much higher than that of usual silicon devices. Problems in the die attach quality result in significant reliability issues. For this reason the manufacturing line testing of these devices seems necessary. The usual structure function evaluation methodology that is regularly used for die attach qualification in after production testing is normally requiring several minutes for the testing of a device that is prohibitively long for inline testing. In this paper various solutions are proposed to overcome the lengthiness of the thermal transient testing and structure function evaluation methodology. With the proposed solutions the necessary time of problem detection is in the order of magnitude of milliseconds, enabling the methodology for production testing.Copyright © 2007 by ASME