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I need a lo-fi way of mounting a PCB (Tessel plus RFID card) under a table.

The easiest method by far would be velcro but I'm worried about static discharge frying my circuitry. Should I be?

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    \$\begingroup\$ If the PCB is inside a metal enclosure, that should help protect against ESD... otherwise if it's just an exposed PCB assembly, it could be vulnerable regardless of how it's mounted. \$\endgroup\$
    – MarkU
    Oct 5 '14 at 5:59
  • \$\begingroup\$ How permanently? Why not just glue in place? Also, I've installed plenty of bare pcbs with just a loop of dielectric tape with no problems. \$\endgroup\$ Jan 8 '15 at 3:50
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The Velcro is probably no worse than any other plastic (nylon) that is close to your circuit, as far as ESD is concerned. It may be a problem if you frequently rip the Velcro off, as you may cause the friction to generate a charge.

But a big problem with Velcro is that it does not last very long. The self-adhesive side will stick OK to begin with, but will dry out and let go in a comparatively short time. I've seen this happen on a regular basis with electronic modules fixed to housings with Velcro. They all came back with the modules dropped off but the Velcro-to-Velcro interface intact. The Velcro had just come unglued from the inside of the housing.

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  • \$\begingroup\$ It's probably not the glue's fault, but poor surface preparation. Today lots of products are held together with double-sided tape. Degrease, abrade, degrease before sticking things down. \$\endgroup\$
    – tomnexus
    Feb 7 '15 at 5:19
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Velcro-type material (hook and loop fastener) is available with many different adhesives. The stuff that we use is from a company called Aplix and it comes with a VERY high strength adhesive. The part numbers we use are Hook: A800R0107H000-R and Loop: A800R0107L000-R

This particular material is white and is 4" (100mm) wide. We use it because it is the only material permitted by Riddell for use in the football helmets they manufacture for Professional Football players.

The adhesive used is from a class called VHB (Very High Bond) and is similar to the stuff used to build, among other things, passenger aircraft. This stuff is that good and that strong.

And, yes. We have used it to mount circuit boards to various objects and surfaces. Just be sure to trim the through-hole leads on the bottom of the PCB so that they don't poke through the material.

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Possibly use a conductive hook & loop material, (beware - the V word is trade marked). With this material static dissipates quickly, if any is generated at all. A bit more pricey but it does exist. See:

http://www.lessemf.com/fabric.html#207 .

http://www.adafruit.com/product/1324

If that doesn't seem well enough use a few simple snap together buttons. One side riveted into the PCB the other side screwed to the table surface.

http://www.artfire.com/ext/shop/gallery_item/DesireMeNow/104098

http://www.coversuperstore.com/Snaps-Grommets-Hardware/

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Usually for a properly designed fully assembled board ESD isn't really a problem. And if I were you unless the desk is made of material that is unsuitable I would just bolt the board to the desk with a few screws. All my boards have mounting holes for this.

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