SMD PLACEMENT USING MACHINE VISION.

Abstract

Placement machines fall into several categories: high-speed machines that place small discrete chips; slower but more precise machines for placing PLCCs and CLCCs; and multifunction machines that do both. Today's placement machines rely purely on mechanical accuracy and precision for board assembly. However, for 25-mil active SMDs, and large 50-mil active devices, tolerance stackups make mechanically based placement machines unreliable. To make the move to these larger devices, users will turn to placement machines that incorporate additional sensor capabilities, such as machine vision.