In power LEDs for lighting use, is there a fault whereby the LED may just suddenly go open circuit because its internal bond wire comes loose and disconnects?
As you know, the bond wire is extremely thin, and its connection from the LED semiconductor piece to the metal terminal tab of the LED is done by cold-welding, which at best, is an in-effective way to connect such things…but has to be tolerated due to the thin-ness of the bond wire.
Also, the brittle bond wire eventually oxidises and just breaks apart. Operation at high temperature, and the temperature cycling, all act further to decrease the life of the LED’s bond wire.
I am seriously wondering if there is any point at all in making a long-life surge protector for a LED streetlight if its just going to fail from a disconnected bond wire.
Bond wires in LEDs…
https://en.wikipedia.org/wiki/File:...35_mm_RGB_Surface_Mount_LED_EAST1616RGBA2.jpg
As you know, the bond wire is extremely thin, and its connection from the LED semiconductor piece to the metal terminal tab of the LED is done by cold-welding, which at best, is an in-effective way to connect such things…but has to be tolerated due to the thin-ness of the bond wire.
Also, the brittle bond wire eventually oxidises and just breaks apart. Operation at high temperature, and the temperature cycling, all act further to decrease the life of the LED’s bond wire.
I am seriously wondering if there is any point at all in making a long-life surge protector for a LED streetlight if its just going to fail from a disconnected bond wire.
Bond wires in LEDs…
https://en.wikipedia.org/wiki/File:...35_mm_RGB_Surface_Mount_LED_EAST1616RGBA2.jpg