PeterC
Newly Enlightened
I haven't (yet), but a recent delivery of Cree XR-E LEDs on star boards from DX prompted me to think about it.
The three items that I received were individually wrapped in plain polythene bubblewrap.
In the electronics manufacturing environment that I work, this would be an absolute No-No! Company policy is that all electronic components or sub-assemblies are handled as if they are electro-static sensintive (i.e. may be damaged by static electricity) and they would all be enclosed in bags and wrappings with appropriate ESD properties. Indeed, we actually take this a little further than might be necessary leading to all items issued by stores being enclosed in ESD bags, be they electronic components or not (such as nuts and bolts!).
I had a look at the Cree device datasheet and they describe the bare devices as being "ESD Class 2 (Human Body Model per Mil Std 883D)". This was still not clear to me, so a quick google search for what this might mean gave me this site: http://www.esdsystems.com/whitepapers/wp_devicesandstatic.html
This website states class 2 as being susceptible to electrostatic voltages of 2000-3999V.
NB. The class applies to hybrids with class 2 devices mounted on them – essentially what a LED on a star board is.
Elsewhere on the website, they show a number of examples of static generating situations. The nearest to my bubble-wrapped stars was removing bubble pack from PCBs. In the most advantageous conditions (when humidity is high – I do live in the UK after all!), the static electricity being generated was stated to be 7000V – significantly greater than the danger levels for these LEDs.
Now, I haven't had chance to try out these LEDs yet (and expect to observe no ill effects when I do), but I'm curious to see if anyone has encountered LED failures that could be attributed to possible ESD reasons from inappropriate wrapping or otherwise.
The three items that I received were individually wrapped in plain polythene bubblewrap.
In the electronics manufacturing environment that I work, this would be an absolute No-No! Company policy is that all electronic components or sub-assemblies are handled as if they are electro-static sensintive (i.e. may be damaged by static electricity) and they would all be enclosed in bags and wrappings with appropriate ESD properties. Indeed, we actually take this a little further than might be necessary leading to all items issued by stores being enclosed in ESD bags, be they electronic components or not (such as nuts and bolts!).
I had a look at the Cree device datasheet and they describe the bare devices as being "ESD Class 2 (Human Body Model per Mil Std 883D)". This was still not clear to me, so a quick google search for what this might mean gave me this site: http://www.esdsystems.com/whitepapers/wp_devicesandstatic.html
This website states class 2 as being susceptible to electrostatic voltages of 2000-3999V.
NB. The class applies to hybrids with class 2 devices mounted on them – essentially what a LED on a star board is.
Elsewhere on the website, they show a number of examples of static generating situations. The nearest to my bubble-wrapped stars was removing bubble pack from PCBs. In the most advantageous conditions (when humidity is high – I do live in the UK after all!), the static electricity being generated was stated to be 7000V – significantly greater than the danger levels for these LEDs.
Now, I haven't had chance to try out these LEDs yet (and expect to observe no ill effects when I do), but I'm curious to see if anyone has encountered LED failures that could be attributed to possible ESD reasons from inappropriate wrapping or otherwise.
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