Most hard drives these days have multiple platters. To remove platters a specialist extraction tool is required. Platters are aligned to very exact specifications. The tracks are packed so tightly that the actuator is unlikely to pick them up after the chassis is opened, even though the user may not have touched the spindle! Platter extraction is a very delicate procedure on any hard drives over 20Gb in size. Once the rotational alignment of the platters has been altered – even by a hundredth of a millimetre - the game is more or less over unless you are prepared to spend big bucks!
Solid state drive and flash media do not use spinning platters but NAND memory chips. These are as difficult to work with due to the size of the chip and the number of pins. Specialist BGA soldering equipment is required and the process has to be completed by hand through a microscope. To disconnect fifty pins on a NAND chip and re-solder this to donor parts is one of the most challenging processes our data recovery engineers undertake. Imagine then having to disconnect the chip for a second time and re-solder it back onto the original media!
As you can see, data recovery is a very challenging and precise skill. One mistake and the engineer has lost everything. This is why when we are sent media from users who have already engaged a data recovery company previously, the success rate drops from 97% to 33%. Give your data a chance and make sure you engage the best possible experts!
Reference: http://www.datarecoveryspecialists.co.uk/blog/hardware-rebuild-of-solid-state-disk