How to differentiate real and fake China IC

hamisu-anguan:
Is there a way to differentiate real IC (OEM manufacture from ST, SGS, TI, Motorola) versus fake China which mark exactly like the OEM ?

If send to decapping, the price is USD200 per IC but they just compare the real which need to provide to them versus the suspect. We dont even know which is real ?

Be aware many chips are ENCAPSULATED in China, but the die was made in America.

Paul