About ESD protection on daughter boards

[mulfycrowh]

Hi everyone,

I have a motherboard with daughter boards.
They are linked together with shielded FFC cables.
I have:
- Daughter boards with connectors only
- Daughter boards with ICs like light sensor

Where do I put the ESD protection?
I think it's better to put it on daughter boards because the shortest path.
What do you think?

[Roky]

Hi
just close to every external connector

this PDF could be usefull


best regards
Rocco

[mulfycrowh]

Hi.
Thanks for reply.
I agree but before connecting the daughter boards to the motherboard, it means that the motherboard is not protected, when assembling the device.

[mulfycrowh]

I suggest to put ESD protection on the motherboard and on the daughter boards?

[robertferanec]

Very simply to say, ESD protection should be placed on the signals where people can touch when the product is completed. It is not necessary to place ESD on the pins which are used for internal connections - boards should be assembled in proper environment (e.g. people assembling boards should have ESD mat, ESD bracelet, ...). Most of today's chips include basic ESD protection, so handling bare boards in proper environment during assembly is fine.

PS: What I do with all my prototype boards - I always handle them the wrong way - no ESD mat, ESD bracelet ... because that is how some people may handle my boards in real world. So if there is an ESD sensitive component, I would like to be the first one to find out and if possible to replace it with something else or protect it before it goes to mass production.