What type of anti-static mat should I buy?

[RogerRowland]

I'm rearranging the house to get myself some more work area as my electronics hobby expands (exponentially!) and want to get some basic ESD protection while I'm working.

I currently just use a wrist strap and my normal desk surface (laminated wood) but I'm getting a new desk that I'll cover with an ESD mat of some description.

Looking at options, I see some conductive mat - http://www.antistatonline.co.uk/product.php/165/black-conductive-mat and also some combination of dissipative and conductive mat - http://www.antistatonline.co.uk/product.php/98/2-layer-smooth-esd-static-mat

The first is much cheaper than the second, but what's the difference and which should I buy? I'm not so concerned with the cost, but just doing the right thing (whatever that is!).

[rs20]

There are multiple EEVBlog episodes about this.

You certainly do not want the conductive mat -- the conductivity will cause interference to your circuits. You want to be able to lay your circuit down on the mat and not be doubting whether your mat is interfering with it.

The static-dissipative-over-conductive mat is that one that's right for the job. Unfortunately, as is often the case, the thing that's right for the job is a bit pricier .

Come to think of it, I can't figure out what conductive mat is actually for??

[RogerRowland]

There are multiple EEVBlog episodes about this.

D'oh - should have thought of that - I'll take a look now, thanks...

Come to think of it, I can't figure out what conductive mat is actually for??

Actually, re-reading my link for that conductive mat, it says "ESD Flooring" so maybe it's just for standing on?

[EEVblog]

[EEVblog]

http://www.antistatonline.co.uk/product.php/98/2-layer-smooth-esd-static-mat

Get that one. You don't want fully conductive.

[RogerRowland]

http://www.antistatonline.co.uk/product.php/98/2-layer-smooth-esd-static-mat

Get that one. You don't want fully conductive.

Thanks Dave - glad to see you respond in person too - I've watched more than a hundred of your EEVblog videos, but must have skipped these! Watching now ... 

[EEVblog]

Thanks Dave - glad to see you respond in person too - I've watched more than a hundred of your EEVblog videos, but must have skipped these! Watching now ... 

It's... not... me... it's... DaveBot

[RogerRowland]

Blimey, it does get a bit pricey though 

I only have a small desk - 915mm x 610mm - so a 900x600 mat is perfect, but then add on wrist strap and cord, grounding plug, cord for the mat, ground point for the front of the desk, etc, plus VAT and delivery and it's already the best part of £100.

How much do I realistically need?

[GreyWoolfe]

Blimey, it does get a bit pricey though 

I only have a small desk - 915mm x 610mm - so a 900x600 mat is perfect, but then add on wrist strap and cord, grounding plug, cord for the mat, ground point for the front of the desk, etc, plus VAT and delivery and it's already the best part of £100.

How much do I realistically need?

That sounds about right.  I have a snap on my mat that this attaches to:
http://www.ebay.com/itm/ESD-Safe-Anti-Static10MM-FEMALE-SNAP-LOW-PROFILE-COMMON-POINT-GROUND-CORD-/251473333375?pt=LH_DefaultDomain_0&hash=item3a8cfa8c7f
That connects to earth ground and that is where my wrist strap plugs in.  This is at the edge of the mat closest to me.  This is a bit simpler and cheaper unless you want to keep your work area neater by using the bench mount and add the mat snap at the side of the mat closer to the wall and run the cord under your workbench to the bench point.  What I used is what I had on hand from a portable esd mat kit that I got from my last job.  If I were starting from scratch, I would put the snap closest to the wall and use the under bench point.  Everyone has their own opinion and we know what opinions are like.  Only you know what is best for you after doing your due diligence.  Think about the most expensive thing you may work on and go from there.  An ounce of prevention is worth a pound of cure.

[Ian.M]

You can get 10mm plated brass or stainless steel press studs for screw mounting from a boat chandler to make up your grounding point by screwing them down to the bench frame through a strip of metal but don't forget 3 x 330K resistors in series for safety between it and the mains plug or water pipe you will use for earthing.   That reduces the extra expense to a lead to connect the mat to the grounding point.

Or do as Dave did in the wristband video and clip to the edge of the mat.  If you put some foil tape wrapped over the rear bench edge to contact the bottom of the mat, and hold the mat in tight contact to it wit a bulldog clip, you can attach a grounding lead to the clip to make a reliable semi-permanent connection.