I see people storing ICs in plastic containers with aluminium foil or ESD foam on the bottom and then put their ICs on top of it to prevent ESD damage.
I dont understand this concept tbh and im confused also, how does it prevent ESD damage ?
My understanding so far:
Plastic is an insulator and insulators store/accumulate charge when rubbed against other insulators. So if the ICs inside the plastic container rattles around, it accumulates charge, this charge cant flow anywhere, then if the potential difference between the IC and the plastic box is high enough it discharges, this could cause damage.
Right so far ?
Ok now putting something conductive between the IC and the storage box solves this problem, but how. What i dont understand is how does it prevent ESD, since aluminium foil is conductive, doesnt it pass the charge to the IC when rattling around ? Makes no sense to me.. The foil is touching the plastic bin and the IC touches the foil, so still everything is connected together or not ?(the IC is still in "direct" contact with the plastic since the foil is conductive )
For me, it seems, its the same like without foil. So how does it work.
EDIT: That foil/foam only prevents ESD damage inside the storage container but not for when i grab the IC, right ?