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I want to transport PCBs mounted with LEDs which are ESD sensitive, in knocked down condition. Standard storage bins are not available in my specific size, hence was thinking to fabricate aluminium bins as per my specification.

I dont have the option of grounding the bins, cause I have to transfer the PCBs regularly form one section to another.

Please help!!

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    \$\begingroup\$ Technically no, aluminium is conductive so if the pins of your PCB are touching the container then it will pass from you through the container to the boards. Why not just use some adhesive and stick antistatic foam inside the aluminium containers to prevent contact between container and PCB? \$\endgroup\$
    – user103993
    Mar 8, 2017 at 13:43
  • \$\begingroup\$ That is not a problem since the metal box will absorb the static charge whereas a small trace on a PCB will not and will pass it on to the ICs. Whatever you do ESD foam is highly recommended though since it will make good contact with the boards and prevent any static from building up in transport whereas the boards might not properly contact a metal box. The metal box is unnecessary but recommended. \$\endgroup\$
    – TWiz
    Mar 9, 2017 at 6:14

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Conductive bins are just fine for transporting ESD sensitive boards. Any protective packing in the bin to avoid mechanical damage to the boards must be conductive, for instance conductive foam. The ground conductor(s) of the board should be in electrical contact with the bin.

You must also make sure you load and unload the bins correctly. Do not touch the boards in the bin without taking the same precautions as for loading and unloading.

When you load a bin, the board and the bin must be at the same potential. This means electrically connecting the bin to the board or board handling kit before, and during, the transfer. This is perhaps most easily done by putting the bin on your anti-static workstation mat, or briefly connecting a ground lead to it.

The same goes for unloading a bin. The bin must be at the same potential as the surface or kit that is to receive the board.

Once the bin is loaded, it can be disconnected from ground, and freely taken to any potential.

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    \$\begingroup\$ The problem is that, under some circumstances, aluminum bins are effectively non-conductive. Aluminum does not rust. Instead, a very thin coating of aluminum oxide forms on any exposed surface, and aluminum oxide is an excellent insulator. Sharp metal will easily pierce the oxide layer, but softer materials (like hands or pc boards) will not. \$\endgroup\$ Mar 8, 2017 at 18:42
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I did my own manufacturing of a telecom product of 20 years. When I started out telecommunications manufacturing was regulated by Bellcore. Manufacturing floors had Bellcore Quality Control Inspectors on site. ESD was a major part of quality control. Some products were manufactured at Siemens Telecom in Lake Mary FL, which met the most extensive of Bellcore requirements.

My product was housed in an anodized aluminum case.

The answer to your question is: Yes., if you anodize the aluminum with Type II or Type III (hard coat, thicker coating), which uses sulfuric acid, the most common methods.

Almost all aluminum products are anodized to prevent oxidation and is inexpensive.

You are not the first to ask this question. There was a study done on ESD on Anodized aluminum for ESD transport container used in automated handling equipment to see if anodized aluminum passes tests set by ANSI ESD standards .

LINK to Study: Anodized Aluminum Alloys Insulator or Not



Regarding some of the comments about ESD handling, they made my skin crawl.

Procedures were not touch this or that first then touch that. Procedures are specified by organizations like ANSI and Electrostatic Discharge Association.

ESD Association has a very general basic procedures. Keeping in mind these guys sell the ANSI documents so they are not going to give it all away.

A guide for implementing the standards is a better and more practical thing to know.

NASA has it own ESD manual which follows ANSI procedures and they do not charge it. It is an overall comprehensive handbook for implementing ANSI/ESD S20.20
Chapter 8, ESDS ITEM HANDLING, is all you should need to know.

NASA HANDBOOK, WORKMANSHIP MANUAL FOR ELECTROSTATIC DISCHARGE CONTROL

LINK: Basic ESD Control Procedures and Materials, EOS/ESD Association



The above should cover the topic, if for some reason it does not, there are volumes of ANSI/ESD standards. The two most applicable would be Wrist straps and Handling Equipment.

LINK: ESDA Document List
LINK: Discharge Susceptible Items, Wrist Straps 2006
LINK: Discharge Susceptible Items,Automated Handling Equipment 2007

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You can safely load and unload PCBs to /from bins, by holding the GND trace of the PCB ----- with your hand ----- and then touching the metal bin ----with your other hand ---- before placing the PCB into the bin.

Key is to discharge any static buildup between you/PCB/bin before moving the PCB.

This same procedure works on removal from the bin: touch the bin with one hand, touch GND of PCB with other, then remove the PCB.

The ESDstrap is just a way of getting a high-value-resistor between you and the bin, so the static does not build up.

Of course, if you go shuffling your shoes on carpet as you touch the PCB, that ESDstrap may not keep the voltage to ZERO as you shuffle.

There are reasons to think about these methods, not just blindly trust.

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    \$\begingroup\$ this is what I do, but it's not what I tell people to do. \$\endgroup\$
    – Neil_UK
    Mar 8, 2017 at 19:22
  • \$\begingroup\$ If the strap is grounded like it is supposed to be, shuffling feet on carpet is not an issue. Often the strap hangs out of the shoe on to a ground flooring. Carpet should not be an issue because it has no place being anywhere where ESD is a concern. It's fine to do as you say if you own the products being handled. If someone other than the owner is handling the products then that person must be grounded. \$\endgroup\$ Mar 9, 2017 at 23:05

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