What kind of motor to use in a PCB drill?
For PCB drilling you want high speed. &lt; 100mA current draw indicates that you have a very 'weak' motor which has low rpm and torque at 12V.

A '380' size brushed motor which produces 25,000-30,000rpm at 12V should be sufficient. For example the Mabuchi RS-380PH-4045 is rated for 3-12V, draws ~0.5A free running, and does 25,000rpm at 12V. 

Many manufacturers make similar motors, and these are commonly used in PCB drill systems. Here is an example on eBay:-

VANGEL--mini pcb drill Press tool 380 motor

Power: 3-12 V DC
Diameter: 2.8CM
Length: 5.2CM
Weight:65g
Rated wattage: 20
Rated torque: 600G.CM           
3V    6915Rpm    0.52A
6V   14395Rpm   0.66A
9V    21095Rpm  0.68A
12V  29326Rpm   0.80A