为便于区分，要将PG net与signal Net设置为不同的shape
pg wires:
deselectAll
editSelect -net * -type special -shape {PADRING STREIPE BLOCKRING} -object_type {wire via}
defOutBySection -selected -specialNetRouting -specialNets -noDiearea my_def.def
signal wires with shielding:
setAttribute -net $net_name -shield_net $shielding_net_name
deselectAll
selectNet -shield
editSelect -net * -type special -shape {COREWIRE} -object_type {wire via}
defOutBySection -selected -specialNetRouting -specialNets -noDiearea my_def.def