test pad and probe pad

Test pads refer to pads of metal that are compatible for bonding; probe pads
are much smaller and are intended for very specialized measurement devices.
Test pads are also defined to be only available on a wafer and are not intended
to be bonded for the final product. These pads are uncovered by the passivation for
the prototyping or evaluation phase and are covered by a glass isolation layer before
it is packaged. In terms of ESD, they are less protected than regular pads because
after testing they will not be connected to the pins of the package.
Probe pads can be placed anywhere on the die, since they are used when
the die is completely unprotected