Material Handling Systems - Development of

The material handling industry dates back to the fifties and the introduction of the first wafer probers. Package handlers evolved during the sixties as a move away from manual insertion and testing. Laser repair developed in the sixties as well. It was first used for trimming precision com­ponents-mainly thin-film resistors in analog circuits. With the advent of memories, low yields demanded that redu·ndancy be used, so a few extra memory cells began to be placed on the chip, laser trimmers were then used to cut connections to the bad cells and rewrite the lines to the good ones.