Have you seen new installed LED street light just went dark after a few day? Have you seen LED traffic light got broken just after a short period of time? Isn't LED lighting suppose to long life? Why do we see so many failure LED around us?
After our study, we find out this is a popular problem among high power LED; less with lower power LED. One of common reason is bonding wire broken.
What's bonding wire? It's a thin wire that connects silicon die and Chip package connector. With high power LED, its chip die can go up and down in a wide temperature range; and due to material can contract and expend at different temperatures, this bonding wire may broke if the die, bonding proxy and connection pad are in an odd arranged position.
Does LED manufacture test their product? Yes, they do, to an extend. their expensive tester machine can make contact to chip connectors without making a solder point. However, they won't occupy expensive tester machine with low price (few dollars) chip for a prolonged time.
So this has to come down to us.
Modules from
Easy LED Lighting are basically tested by China manufacture, so they do work. But after we were into this business a while, we found out there are a low percentage of modules would fail after just a few days of usage; otherwise, they would work for a long long time.
Right now, we burn in test our kits products, every kit will gone through a 10 hours burn-in process with on/off sessions control by timer, just to ensure their quality.
No comments:
Post a Comment