3 ms·
I'm pretty sure that the "plastic cover" is in fact made from copper, and I'm pretty sure that the GP is asking about this cover is not shorting out the pins, w
by beAbU 2y ago
I'm pretty sure that the "plastic cover" is in fact made from copper, and I'm pretty sure that the GP is asking about this cover is not shorting out the pins, which is sure looks like it does.
I assume this cover is supposed to be removed after installation. So I think you are right in assuming it's purpose is there to avoid ESD damage during handling.
- adrian_b 2y agoYou might be right and the cover is made of copper sheet, in which case it must be very oxidized to have this color, which would diminish its role of ESD protection. Wasting so much copper sheet for a cover that will be dumped during the PCB assembly is not wise, but in the Soviet Union they were rather careless about wasting materials, so this would not be unusual. For other early MOS ICs or transistors, which were similarly sensitive to ESD damage, the vendors did not use so big covers, but only a metallic clip made of thin elastic wire, which was applied on the pins and which pressed on them until removed, due to its elasticity, providing thus a short circuit to avoid discharges. However any such metallic shorts raised the cost, so they were replaced with delivering the ICs either contained in tubes made of conductive plastic or inserted in black sponges made of conductive foam.