ESD mat? - again again but maybe a bit deeper.

[FriedMule]

I know that there are a lot of questions about ESD mats and a lot of opinions but what I am trying to do, is to understand why and what.

You can get 1, 2 and 3 layers in vinyl, rubber and other materials, in all sort of combinations. You can different thicknesses and you can buy from alibaba, ebay, amazon digikey and so on. So a bit of a jungle. :-)

What do you choose for a table surface where everything is being done? Measuring, building, cleaning and yes everything... even sleeping:-)

[MarkF]

I can't see that the material matters if it is covered by the ESD mat.
Mine is wood with a polyurethane finish.

However, I now have two desks.  One for testing and one for soldering.
I found that I was getting little solder flecks all over the mat and did not want them around when testing.

[jpb]

I think perhaps you are worrying too much.

The key thing is you want a high resistance path to ground for electrostatic charge to dissipate away but not do so too quickly.

So you want a mat with a conductive layer which connected to ground normally via a stud and cable to a house earth connection but it can be to any other earth.

The top layer of the mat should be a high resistance dissapative (I've spelt that wrong) layer which will conduct enough to remove any low charge high voltage static but not enough to short out any circuits you're working on or to provide a dangerous earth connection if you're working with high voltages.

Underneath any sort of wooden bench or table is good. I would avoid metal, not because of ESD but from the safety point of view - if one hand accidentally comes in contact with a mains connector and the other hand is on an earthed metal table then you may electrocute yourself.

As to the material of the mats - rubber is better quality than vinyl but costs more. I'd avoid anything too cheap - I have a silicone mat that is supposed to be ESD safe but when I measure its resistance with my Fluke insulation meter it comes to over 10 Gohms (the limit of my meter) so I suspect it may actually be insulating.

The quality of the material is more important for such aspects as how well it survives you spilling hot solder on it.

[FriedMule]

I thank you for your reply's, my concern, right now is then about what to buy. The prizes jumps in all directions and if you buyy from i.e. Digikey, you do really pay for it, up to about $1000 for 4 sqr feet!!
I have a wooden table that measures 2 meter by 1 meter.

[MarkF]

I bought the Sierra FT Series, Dark Blue from All-Spec:
   24"x48" was $54.00 USD

-FT Series 36"x72" Dark Blue:
   https://www.all-spec.com/Catalog/Static-Control/Static-Control-Matting/ESD-Safe-Rubber-Benchtop-Mats/FTW160DB

-FS Series 36"x72" Gray:
   https://www.all-spec.com/Catalog/Static-Control/Static-Control-Matting/ESD-Safe-Rubber-Benchtop-Mats/FSW160G

[jpb]

I thank you for your reply's, my concern, right now is then about what to buy. The prizes jumps in all directions and if you buyy from i.e. Digikey, you do really pay for it, up to about $1000 for 4 sqr feet!!
I have a wooden table that measures 2 meter by 1 meter.

I think the very expensive ones are for clean rooms - you clearly don't have those requirements.