Grid array inspection system and method

Abstract

A high speed, high accuracy, three-dimensional inspection system for ball and pin grid assemblies. The system uses a three-dimensional scanner to gather data which is analyzed to yield height position measurements along with overall packaged dimensions. The grid array to be scanned is placed upon a fixture above a motion control table. The motion control system is controlled by a personal computer and has a high resolution. The parts can be presented in single trays, tray stackers, tubes or other carriers. Array packages are handled either manually or automatically. In the manual mode, arrays are loaded onto the fixture by hand before activated the image processing hardware. Alternatively, an automatic pick and place module may be used to load the grid array packages on the fixture. The fixture consists of a plate with a cavity the size of the grid array package being inspected. The size of the cavity can be adjusted to fit different size parts. In addition to the height and position measurements, measurements of spacing, coplanarity, standoff, grid pitch, ball diameter, ball position, and package warp can be performed. With regard to pin grid arrays, bent or missing pins can be detected with the system. With regard to ball grid arrays, missing balls can be detected.