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16 Jun 2016, 11:42

Are the tools and accessories on your workbench ESD safe? - Part 1

In a previous post we talked about 2 types of materials you should be aware of in an ESD Protected Area (EPA): insulators and conductors. We learned that one way to protect your ESD sensitive devices (ESDs) is to replace regular insulative items with an ESD protective version. But exactly what items can and should you replace? Well, that’s what today’s post is all about. We put together a list of the most common items used at a workstation and explain in more details why they should be replaced and what options you have.

Conductors and Insulators

Materials that easily transfer electrons (or charge) are called conductors and are said to have “free” electrons. Grounding works effectively to remove electrostatic charges from conductors to ground.

Materials that do not easily transfer electrons are called insulators or non-conductors. An insulator will hold the charge and cannot be grounded; therefore, the charge cannot dissipate in a controlled way. This could lead to static damage of nearby sensitive components as there can be a rapid, spontaneous transfer of electrostatic charge.

So how do you control static electricity in the workplace? Easy - just follow these principles:

  • Remove all unnecessary non-conductors,
  • Replace all non-conductive materials with dissipative or conductive materials and
  • Ground all conductors.

So what insulators in your EPA can be replaced with dissipative of conductive materials? Here is a list of the most commonly used insulative items and their replacements:

Document handling

Paper is everywhere in the workplace and an ESD Protected Area is no exception. The problem with regular paper is that it is insulative but tends to be low charging because it is hygroscopic (readily absorbs moisture). The primary concern with paper is placing ESD sensitive items on the paper interfering with the path-to-ground of the grounded ESD mat. Best practice is to use dissipative paper or have regular insulative paper in dissipative document holders or wallets.

Dissipative Self-Stick Notes
Dissipative self-stick notes

EN 61340-5-1: “Paperwork inside the EPA shall either be kept in containers conforming to the requirements of table 2 or shall not generate a field in excess of that specified in paragraph 5.3.5 (ESDS should not be exposed to electrostatic fields in excess of 10 kV/m).

There are a number of products available on the market that can assist with handling documents/paper in ESD Protected Areas:

  1. ESD safe document holders and wallets
    Document wallets and holders are designed for use within ESD Protected Areas in accordance with EN 61340-5-1. They are static dissipative which means charges are removed to ground when placed on a grounded working surface or handled by a grounded operator.


    Examples of ESD safe document wallets and holders

     
  2. ESD safe ring binders and clipboards
    Ring Binders and clipboards are designed to replace high charging insulative regular binders for use within ESD protected areas. They come in different widths with different ring sizes and 2 or 4 rings. Just like document holders/wallets they are static dissipative so charges are removed to ground when placed on a grounded working surface or handled by a grounded operator.

    Examples of Ring Binders and Clipboards
    Examples of ESD safe ring binders and clipboards - more information

     
  3. ESD safe letter trays
    Generally conductive, any electrostatic charges on letter trays are removed to ground when the tray is placed on a grounded working surface or contacted by a grounded operator. They do not require separate grounding when laid on a grounded surface.

    Letter Tray
    Examples of ESD safe letter tray - more information

Cups 

We all love our cup of tea or coffee in the morning and most of us have water bottles on stand-by throughout the day to stay hydrated. But do you know how much charge a foam or plastic cup generates? Well, let’s just say it’s enough to damage your precious components! The answer: ESD safe drinking cups and water bottles. There aren’t too many options out there so make sure you do your research before purchasing. ESD safe water bottles are generally dissipative so charges are removed when placed on a grounded surface or handled by a grounded operator.

MENDA Drinking Cup
Menda drinking cup

One option for a drinking cup (for hot drinks) is the MENDA insulated drinking cup. It is low charging and the stainless steel portion is grounded when picked up by a grounded operator or when placed on a grounded ESD worksurface.  

Read the follow-up post here  

Desco Europe is the newest brand in the Desco Industries family, consolidating our two previous UK-based brands, Charleswater and Vermason. Desco Europe sells the full range of DII products, manufactured in our facilities in the USA and UK, servicing the European market via trained distributors who will sell the Desco Europe value package and complete ESD solution to all ESD users in their territory, leading with hi-end solutions that mark us out from the competition.

16 Jun 2016, 11:42