A method for verifying scan precision of a laser measurement machine
includes the steps of: preparing a standardized BGA model; measuring Z
coordinates values of each solder ball peak of the BGA model for certain
times; determining a Z coordinates conventional true value of each solder
ball peak; measuring X, Y coordinates values of each solder ball centre
of the BGA model; determining a coplanarity conventional true value of a
seating-plane; determining an optimum scanning mode; determining optimum
scanning parameters under the optimum scanning mode; scanning the BGA
model under the optimum scanning parameters and the optimum scanning
mode; obtaining X, Y, Z coordinates values of each solder ball peak;
evaluating the veracity of Z coordinates of each solder ball peak;
evaluating the veracity and repetitiveness of coplanarity; and evaluating
scan precision of the laser measurement machine.