Hi all,
I have been a System Engineer for over 30 yrs and have gone from tubes to ICs during my time in the Aero Space industry.
Tubes were virtually immune to ESD (Electrostatic Discharge) and could be handled just about any way we wanted to. But when it comes to ICs, ESD can damage or destroy an IC in an instant.
Many of the boards offered for sale in kits by DIY Drones contain static sensitive parts/components that can be damaged even when attached to their respective circuit boards.
Therefore it is extremely important for all of you who have built or intend to build DIY Drone kits to exercise basic ESD handling procedures:
1) Buy a static safe pad/mat and attach it to the closest earth ground that you have access to. This will help to prevent static discharge from destroying the static sensitive parts on the DIY Drone boards.
2) Buy a metal wrist strap and attach it to the static safe pad to insure that you are at the same potential as the work pad so that you can pick up a static sensitive board and not risk destroying it with a static charge on your body.
3) Keep all of your completed boards in static safe packaging. Try to minimize board contact with the foam in the foam aircraft.
4) Buy a temperature controlled solder iron with a grounded tip.
If you follow these simple tips concerning ESD and your static sensitive circuit boards, you will most likely have a project that works the first time and will not suffer a latent defect while your plane is high in the sky!
Just a thought.
Regards,
TCIII
I habitually touch the surface first before picking up a device, touch the bag to the table before opening, touch hand back down before putting chip / board back down. I do sometimes clip the solder iron ground line onto the board or handy-hands, so the iron is grounded to same level.
I don't roll around on carpet holding chips, etc. Haven't had any trouble yet.
I think that a tinfoil CSH is a great idea, it should be especially effective. ;>)
The problem with discussing problems in terms of ESD, is that it allows the designer to ignore design failings by claiming "God did it." (The specious claim of ESD). I would submit that the likelyhood of blaming ESD is directly proportional to the non-attention paid to deice specifications.
Some believe it is "ESD", while in reality there exists the potential for a 12x overvoltage on the mux chip if powered up in the wrong sequence. The benefit of finding a real problem is that it has a real solution, while the fictive "ESD" problem can't really be solved.
Hmm, I'm actively developing and building things with IC's of all kinds in/on them for 18 years without ESD protection, and have not once had a single chip fail due to ESD etc. The only times chips died were shorts and very bad ones at that - think high voltage into low voltage tolerant parts with associated magic smoke escape.
If I want to be on the safe side or think I have a charge I just touch a grounded object before working with the chips.
For production(as in not for your own use but sale etc) ESD considerations are of course different since consistent quality control is a necessity.
Here is an article that may help you out. for electronics bays. I can tell you that designing for ESD protection in equipment is not easy and you have to make a choice between reliability and price.
@Mark,
So everytime I am frustrated, I think - I blew the chip - and I get another, and same problem, and in all these years, the problem has never been a chip which mysteriously went bad. Now - over driving motor control chips is a completely different matter, but no amount of tin foil is going to protect you from an overdrive.
Ben
CMOS can suffer partial damage from static causing intermittent behavior that is more difficult to pinpoint when troubleshooting system problems, but it is rare due to protection circuits.
I have been handling microchips from PIC to Freescale to the Arduino all my life without EDS.
Anything is possible, but bear in mind, an op amp no longer costs $50 a chip, and microchips are no longer a few hundred buck a pop. We're talking about a $300 investment to protect a $3 chip from a rare condition. Lighten up already. Aside from which, almost all of these chips have clamping diode on their I/O. Largely this problem has been designed away, and is certainly cost-obsolete for a hobbiest.
Caveat: I've lived in CA and NC with high humidity. If you live in CO or AZ, NM, NV? etc... you might reconsider the problem. Here's a simple test, if you twitch unconsciously before touching your parked car for fear of getting shocked, or if you have developed a habit of touching doors with your keys first to avoid being shocked, you might benefit from the tinfoil hat advice. otherwise, live a little, risk that $2 microchip.
Are there any DIY or purchasable static safe hard enclosures that can be mounted inside the model aircraft? They would serve not only to mitigate static, but also to protect the boards/components physically.
Comments
I don't roll around on carpet holding chips, etc. Haven't had any trouble yet.
I think that a tinfoil CSH is a great idea, it should be especially effective. ;>)
The most immediate example of "blaming god" might be therecent failures of the mux chip on Ardupilot.
Some believe it is "ESD", while in reality there exists the potential for a 12x overvoltage on the mux chip if powered up in the wrong sequence. The benefit of finding a real problem is that it has a real solution, while the fictive "ESD" problem can't really be solved.
If I want to be on the safe side or think I have a charge I just touch a grounded object before working with the chips.
For production(as in not for your own use but sale etc) ESD considerations are of course different since consistent quality control is a necessity.
So everytime I am frustrated, I think - I blew the chip - and I get another, and same problem, and in all these years, the problem has never been a chip which mysteriously went bad. Now - over driving motor control chips is a completely different matter, but no amount of tin foil is going to protect you from an overdrive.
Ben
Anything is possible, but bear in mind, an op amp no longer costs $50 a chip, and microchips are no longer a few hundred buck a pop. We're talking about a $300 investment to protect a $3 chip from a rare condition. Lighten up already. Aside from which, almost all of these chips have clamping diode on their I/O. Largely this problem has been designed away, and is certainly cost-obsolete for a hobbiest.
Caveat: I've lived in CA and NC with high humidity. If you live in CO or AZ, NM, NV? etc... you might reconsider the problem. Here's a simple test, if you twitch unconsciously before touching your parked car for fear of getting shocked, or if you have developed a habit of touching doors with your keys first to avoid being shocked, you might benefit from the tinfoil hat advice. otherwise, live a little, risk that $2 microchip.
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