Hi,
I had a pilot call me today and he had bought a PowerExpander Eq10 at a swap meet recently. He installed it but found that if he flexed the unit that it was intermittent. This brings up something that we should all think about. Care and feeding of our electronic equipment. One thing you should realize is that the material printed circuit boards (PCBs) are made of, typically FR4, is sensitive to humidity. High humidity can cause the FR4 to swell and warp. This can cause micro-fractures in the joints between the IC legs and the pads on the PCB. I think this may be what this pilot was seeing, the Eq10 had been stored in a high-humidity environment and when he brought it into his shop it probably released some of the water vapor. So, what I am saying is you should try to store all your electronics in controlled humidity environments. Short exposure to high-humidity is not a problem but storing your electronics in high humidity for months and then going back to a dryer environment will cause all your PCBs (receivers, servos, etc) to swell and then shrink. The connections between the current generation ICs and the PCBs is so small that expansion and contraction can cause problems over time. The new lead-free solder (as mandated by RoHS in various countries and now used in all manufacture of electronic equipment except military equipment) is not as tolerant of this behavior as the old leaded solder was. And speaking of lead-free solder, the other reason lead was added to solder was to eliminate an issue called "whiskers" (http://www.nbcnews.com/id/21151552/w.../#.UUHspzdc1Kg). Tin will spontaneously start growing whiskers which can bridge the space between pins on an IC package and eventually cause a short. Some of the failures in the Toyota throttle control issue were traced back to tin whiskers growing on the IC pins. The whiskers tend to grow in high electric fields so any place you have higher voltage or higher currents they are more likely to grow. The basic idea here is that your electronics are not going to last as long as those manufactured with lead based solder so you should keep that in mind when keeping receivers and servos 10 years. Most lead was abolished in electronics manufacturing around 2002. Anyway, I hope this sheds some light on electronics life issues and how to store your equipment.

Thanks Bob! I love how safety regulations leads to inferior products. Thank you government!

so, you recommend replacement every decade?

Here is a question- I had a buddy who was having a problem with one of his video cards, and he read somewhere that if you bake the card for a few hours at 450-500*F it would melt the solder in the joints just enough to mend any small breaks, and melt the whiskers. It worked for him- he's been using the same video card for another 3 years without issues.

I know there is no way you would recommend this for your products, especially with the soft wire shielding, and other nylon parts, but can you see how that would work?

Will you build my my new EQ 10's with lead solder please? I don't need whiskers, and live on the coast, with high humidity.
RUTNBUC
Special order of coarse.

I installed a/c in my shop years ago just for that reason. Texas coast. Real thick air and petro chem refineries all over. I have seen this on the job also on the processing equipment I service.

Here's a dumb question !! I wonder if we could take our recievers apart & find these little whiskers & remove them, somehow ? !! I have almost a thousand dollars in recievers alone & most of them are about 4 yrs. old now. Just a thought but thanks for the great info Bob !!

Very informative post...thanks guys.

I'm wondering if circuit boards could be "potted" in epoxy, or wax, or something to keep this kind of thing from happening?

How about keeping those little packages of absorbent material you see in some products in our planes during storage?

Hi,
I would say 10 years is a pretty good life time for any electronic product. There are other issues, like metal migration inside the ICs themselves (the fine metal traces inside ICs are subject to high electrical fields because they are so close to each other, and the metal starts to migrate between gaps) and this is only getting worse as the dimensions of the parts inside ICs shrink.

Basically you are trying to reflow the solder a bit when you do this. It may or may not work. Solder with lead melted at 280-320 degrees C. Solder without lead melts at around 400-500 degrees C. Thats 750 degrees Fahrenheit. So, this may work OK with older boards but I am guess it would be much less effective with new boards made with leadless solder. Also, most assemblies will have some parts that cannot stand the heat. Through-hole parts cannot stand reflow soldering in general. They are added after the initial surface mount assembly and are run over a wave of melted solder on the back of the board but the actual part is never raised to the temperature that melts solder.

Originally Posted by Brutimus

Thanks Bob! I love how safety regulations leads to inferior products. Thank you government!

so, you recommend replacement every decade?

Here is a question- I had a buddy who was having a problem with one of his video cards, and he read somewhere that if you bake the card for a few hours at 450-500*F it would melt the solder in the joints just enough to mend any small breaks, and melt the whiskers. It worked for him- he's been using the same video card for another 3 years without issues.

I know there is no way you would recommend this for your products, especially with the soft wire shielding, and other nylon parts, but can you see how that would work?

I suppose you could do this in some cases but in general it would be cost prohibitive.

Originally Posted by Brutimus

I'm wondering if circuit boards could be "potted" in epoxy, or wax, or something to keep this kind of thing from happening?

In order for those to work you need a sealed environment.

Originally Posted by Siko_Flyer

How about keeping those little packages of absorbent material you see in some products in our planes during storage?

Just thinking out loud here. I wonder if washing the components with RO water would remove said whiskers. I know this is done in some manufacturing after soldering before epoxy sealing the PCB. This removes all the residue.

Everybody raves about Mr. Ritchey's products,and here we are trying to figure out how to make them last longer.I doubt I will have any plane that survives 10 years.On another note,I just bought my first Smart-Fly product,a PE EQ-10.There was an issue with my card and Mr. Ritchey called me and we got it resolved,he even called me again to tell me it shipped.This was Wednesday and it was in my mailbox today.Most places that have an issue with a card will just not ship and leave the customer wondering where their stuff is.Thanks Mr. Ritchey for the top notch customer service

Ok Then, What is everyones thought about storing your planes in the basement. The temp is pretty much the same year round, I use an EQ6 in all my 100cc birds.

All my planes are in a finished basement- but I live where 30% humidity is a wet day!