toothbrush is it ESD safe?

[lynx]

Hi

i've got a circuit board sensitive to ESD which i need to clean it from flux residues but i can't wait till i receive an anti static brush which i ordered from Ebay...

i was wondering if there is a way to discover if a simple toothbrush can clean the pcb without harming the sensitive components...

also i want to know what is the "Dissipative polypropylene"?

 

[crutschow]

Most plastics can generate static electricity. Natural bristle brushes usually are safe.

"Dissipative polypropylene" means that it is slightly conductive to allow the bleed off of static charges.

 

[lynx]

hi

how can i know if what i bought is really a conductive plastic? can i measure resistance? if yes how many Mohm i should expect?

concering the toothbrush i'm not sure if you find it funny or not but many people use it to clean a PCB, but from your sayings i understand
it should avoided right? is there any way i can see if it is made from a plastic which is safe?

 

[Reloadron]

If you want to check or test an ESD work surface you use a Megger set at 500 Volts. Attached is an image of the setup. I forget the distance but I am sure it is out there in an ESD specification. The weights are 5 Lbs. I remember that much.

Since you mention flux removal on an ESD sensitive board we can assume the board was already worked on. Should that be true was the work done on an ESD approved workstation surface? When the board is handled are ESD wrist straps worn? Because if this board has been handled sans ESD work procedures and specifications this is all a moot point.

Maybe give this a read for starters.

Ground the toothbrush through a 1 M Ohm resistor.

Ron

 

[crutschow]

Ground the toothbrush through a 1 M Ohm resistor.

Grounding a standard plastic toothbrush would have little effect on static built-up in the brushes.

 

[Neal]

Wouldn't it be easy to put the pcb in a grounded metal pan in the cleaning solution. There should be no static problems this way, would there?

 

[crutschow]

Wouldn't it be easy to put the pcb in a grounded metal pan in the cleaning solution. There should be no static problems this way, would there?

If he immersed it in the cleaning solution, but typically you just dip the brush in the solution and then clean the board out of the solution.

 

[Mr RB]

If the plastic bristles and PCB were wet with cleaning solution would it even build up static at all? I thought you need quite dry air?

 

[crutschow]

If the plastic bristles and PCB were wet with cleaning solution would it even build up static at all? I thought you need quite dry air?

I'm not sure. But if the cleaning solution is non-conductive then you might still have static build-up. The reason dry air makes static worse is that the moisture absorbed on the surface of a dielectric when the air is humid forms a conductive path for the charge.