ESD Packaging Guide for PCBs

Introduction:

When handling and packaging PCB assemblies there is an invisible threat called ElectroStatic Discharge (ESD).

ESD occurs when a static charge has built up in a material or person and that charge is released on to another object. Normally this is not a concern – if the charge is large enough you may hear a ‘click’ or feel a sharp jag when the charge is transferred to another object. The charge can range from a few hundred volts to several thousand.

Electronic assemblies are vunerable to ESD. The devices mounted to a circuit board can have small operating voltages in the range of 1.8v to 12v. If a static discharge is released on a device the energy can fry the wafer inside.

For more information about ESD and electronic components please see this page on the ElectronicsNotes website:
https://www.electronics-notes.com/articles/constructional_techniques/electrostatic-discharge/esd-effects-how-affects-electronics.php


ESD Protection Items:

When handling a PCB you should earth yourself first to prevent the buildup of static.
The easiest way to do this is to wear an ESD strap:


The strap goes around your wrist, and the croc-clip end connects to any metallic object that is earthed. Ideally this would be an item that is plugged into a mains socket like a PC.
Do not be fooled by “wireless” ESD straps as advertised on eBay / AliExpress etc – these DO NOT work as there is no direct connection to Earth.

There are ESD plugs you can buy that plug directly into a mains socket and have an Earth connection on the back of it. Only the Earth connection is used – the Live and Neutral pins on the plug are plastic.



To protect the PCB from ESD damage during transit the item should be placed inside a Static Shielding Bag.
Any item placed inside the bag will be shielded from any ESD threat from the outside.



There are other ESD packaging products available. These are detailed below.
These items are ESD safe because they do not generate static but they offer no protection from ESD.


The Pink ESD Bag:
These are used for storing ESD sensitive items in an ESD safe area.
Offers no ESD protection
If the components are to be shipped then this bag must be inside a Static Shielding Bag.



The Pink ESD Bubble Wrap:
Offers physical damage protection during shipping / handling.
Offers no ESD protection
If components or a PCB is to be shipped then this bag must be inside a Static Shielding Bag.



Packing a PCB for shipping:

When preparing a PCB for shipping you can either:
1. Wrap the PCB in ESD bubble wrap, then place into a Static Shield Bag
.. or ..
2. Place the PCB in the Static Shield Bag, then wrap in ESD bubble wrap

If your PCB has any sharp items that are liable to punchure the Static Shield Bag consider removing them first, or wrap the PCB in ESD bubble wrap before putting it in the Static Shield Bag.


Shipping Example:
We are going to ship the PCB below:



Place the PCB inside a Static Shield Bag.
If you cannot find a Static Shield Bag large enough for the PCB you can use two but make sure all of the PCB is covered.



Finally, cover the item using ESD Bubble Wrap to protect from physical damage.



Gallery of Errors:

Over the past year I have received many Novation Supernova II PCBs through the mail needing a DAC repair.

Most of the PCBs have been packaged correctly for ESD protection, but a few notable ones have made it through that raised an eyebrow.

Primarily the senders of these PCBs are musicians with no electronics experience. Some owners may have electronics experience so are ESD experienced, but most are not so the packaging errors are understandable.

Item #1:
Packing the PCB in newspaper was not the worst practice. The paper itself is not a big static generator, but offers no protection.
Try to avoid using paper as packaging.



Item #2:
Standard plastic wrap is a good generator of static.
Please do not wrap a PCB directly in this stuff.



Item #3:
This was wrapped in many layers of cling film. If you have ever used cling film you will have noticed that it sticks to itself.
That’s the static build-up in the film generated when it comes off the roll.
Please do not wrap a PCB directly in this stuff.



Item #4:
ASDA “Save Money. Live Better”
Please, no shopping bags.



Item #5:
This PCB had expanded polystyrene directly against the board on the top and bottom.
Although offering physical protection this material generates static so must be avoided.
There were parts of Static Shield Bags wrapped around the outside but this was offering no protection.



// END

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