Primordial black hole and micro black hole are the same thing?

No, they are NOT the same thing at all. 

Not necessarily. A primordial black hole is a black hole formed at or shortly after the Big Bang. That doesn’t necessarily have to be a micro black hole. Generally, the term micro black hole is a small black hole that evaporates through Hawking radiation very quickly. A primordial black hole can be big enough to have lasted to the current time - and long after.

To give you some idea of values, a micro black hole with a mass of a microgram will last on the order of a plank time, somewhere around 10^-44 seconds.

A primordial black hole with the mass of the earth (radius of 8 millimeters) will last 10^50 years and still currently be gaining mass by being colder than the CMBR.