Wafer image (ads) vision system to automated dimensioning equipment

Abstract

In a semiconductor manufacturing process in which wafers are analyzed using a wafer image (ADS) vision system and automated dimensioning equipment (ADE), an automated communication interface system is provided. The interface system uses a programmable logic controller in combination with relays to communicate signals between the ADS vision system and the automated dimensioning equipment in response to signal indications in both. The programmable logic controller includes a plurality of timers for generating signals of selected duration as well as time delays of selected duration. The relays permit signals to be communicated in the face of signal system incompatibility between components. When a wafer in the automated dimensioning equipment is ready for optical analysis, the interface system responds by sending a start signal to the ADS vision system, which responds by analyzing the wafer and providing accept or reject indications. Signals representing the accept or reject indications are communicated to the automated dimensioning equipment, followed by an enter signal which is required by such equipment. The interface keeps track of the number of times the ADS vision system takes longer than a first predetermined time interval to provide an accept or reject indication, and sets off an alarm when the accept or reject indication does not occur until after a second time delay.