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USB Thumb-drive Secret(r/pics)
OP was surprised to find that the memory chip in his thumb drive was socketed. I.e. a standard type that can be replaced.
Earlier, lower density USB thumb drives might have used chip-on-board mounting where the memory chip was soldered down and perhaps covered with epoxy, thus not removable. But now that MicroSD is a standard it makes more sense to design for that style since they are produced in very large volume. Thus the thumb-drive designer only has to deal with placing a socket, as opposed to the more advanced assembly technology. Also the MicroSD cards are easier for him to buy in modest volumes compared to buying chips/wafers directly from the memory supplier.
I happen to have one of these in my pocket which is the same thing only the MicroSD socket is user-accessible: www.amazon.com/Kingston-microSD-Memory-Reader-FCR-…