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Some people warn against removing an item (eg. a graphics card) from an anti-static bag and placing it on top of the bag. Others say the bag should be turned inside out. Others say there's no problem.

Is there a definitive answer? (preferably with scientific proof)

Fidel
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  • Depends. Summer or winter? – winny Jul 14 '16 at 21:55
  • Interesting, is that really a factor? – Fidel Jul 14 '16 at 21:58
  • I've heard that MOSFETs could get damaged if you touch its gate, because there could be enough voltage created. Never really damaged anything, haven't hear that anyone did – Artūras Jonkus Jul 14 '16 at 22:17
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    This may be a duplicate http://electronics.stackexchange.com/questions/198560/anti-static-bags-safe-to-support-powered-circuit-boards – Voltage Spike Jul 14 '16 at 22:22
  • Actually that question is related to powered electronics – Fidel Jul 14 '16 at 23:22
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    @Fidel - Hi - (a) While there is an answer to your main question, supported by expert explanation, which I can write-up if needed, the underlying question is: Why would anyone want to do what you describe? It suggests there isn't a correctly grounded ESD mat available, and yet someone has taken an ESDS (ESD sensitive device) out of its bag? Shouldn't you be asking *those* people why they are doing *that*? (b) I assume you are referring to ESD shielding bags (grey partly-transparent)? The answers vary with other types. (c) IMHO you may never convince the people whose previous advice you listed. – SamGibson Jul 14 '16 at 23:53
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    @SamGibson people do it. Murphy eggs them on :-) – Russell McMahon Jul 15 '16 at 05:11
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    Fidel - damage CAN and does happen once a bag is opened. There are documented instances of devices being destroyed when customs officials removed tubes of ICs still in their tubes from bags for inspection. | You are dealing with 10's of kV worst case. The very act of pulling a tube or similar from a bag may generate charge and/or allow external charge to transfer. |A charged person may transfer charge to a device and placing the device on an earthed surface may cause rapid discharge and damage. ... – Russell McMahon Jul 15 '16 at 05:15
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    ... While DANGER OF ESD damage is often overhyped it DOES happen. I have experienced repeated ESd death of components which were killed by an unexpected means and where fatality rate dropped to zero when practices were changed. – Russell McMahon Jul 15 '16 at 05:16
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    @Fidel Indeed! In the winter when you have say 50 % relative humidity outside and -20 degrees, heat it up to +20 indoor and you end up with 1 % RH instead and the dangers of ESD increases with orders of magnitude. I don't buy into that not placing boards on anti-static bag at all. – winny Jul 15 '16 at 07:35
  • This question could have been answered with a google search https://en.wikipedia.org/wiki/Antistatic_bag . I know that the pink/blue polyethylene bags provide inadequate protection because the anti static layer can wear off and then your left with a plastic that likes to behave like a dielectric. The mylar ones are better because they have a thicker layer of aluminum, but the protection only works if its inside the bag (Faraday cage). The outside of the bag is made of plastic and it sounds like they try and keep it the same potential but there are no guarantees. Use an anti-static mat – Voltage Spike Jul 15 '16 at 18:06
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    This is not off-topic find a better classification for closing – Voltage Spike Jul 15 '16 at 18:07

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Depends. Anti-static protection is broken once you open the package. If you place the graphics card outside the bag, it will be easy for any charged body(say human hand) to come in direct contact with the graphics card and damage it. So, it's better to place the graphics card inside the bag.

There are 2 types of anti static bags:

  1. Dissipative anti-static bags(Transparent or pink in color)
  2. Conductive Anti-static bags(Metallic/Silver in color)

Dissipative bags are generally made of polyethylene with a static dissipative coating on them. They dissipate charge to any surface that comes in contact with the bag or to the atmosphere itself with the help of tallow amine that is present on the surface of the bag. They are called anti static since they prevent charge build up on their surface. But, they are not charge resistant. If a charged body comes in contact with the bag and if the bag is tampered, the charge would easily damage its contents. So be careful in handling static sensitive components.

Conductive anti static bags HAVE A LAYER OF CONDUCTIVE METAL ON THEIR OUTER SURFACE. IN THIS CASE, PLACING THE GRAPHICS CARD ON TOP OF THE BAG MAY DAMAGE IT SINCE THE OUTER LAYER IS CONDUCTIVE. These type of bags are used for very sensitive components.

If you are unsure about the type of anti static packing you are using, make sure you place the graphics card inside the package when not in use and wrap it up properly.

E.Basu
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    How would the conductive layer of the bag damage the unpowered device? The device already makes similar contact when **inside** the bag, surviving handling/packing/shipping. – user2943160 Jul 15 '16 at 04:20
  • The inside of the bag WILL NOT be conductive. The outer surface could damage it, if the graphics card was powered few seconds before it was placed on the bag. The capacitors would still be charged and the conductive layer could short the metal contacts. Also, assuming the bag has come in contact with a charged body, the charges would be residing on the outer surface of the bag. – E.Basu Jul 15 '16 at 04:25
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    Grabbing a nearby silver anti-static bag and a DMM: the surface conductivity of the bag at low voltages is still in the *overload M\$\Omega\$* range. The <12V of the capacitors in consumer PC components will discharge more through your hand, which has measurable, 1k-1M\$\Omega\$ resistance. – user2943160 Jul 15 '16 at 04:32
  • To add: when I work on my PCs, I often use the bare aluminum/steel side panels (good conductors) as holders for components on their way in/out of the system. Touching the panel puts everything on it at body potential, allowing the components to be safely picked up. Since the computer powers down completely before disassembly, there's almost no power left in the capacitors. – user2943160 Jul 15 '16 at 04:54