Substrate machining verifier

摘要

A system for machining and for verifying the machining of substrates includes an energy beam located to impinge upon machined features of the substrates and a photodiode switching circuit matrix for detecting those portions of the energy beam which impinge upon the machined features of the substrate. The photodiode switching circuits include a current boost resistor in parallel with the photodiode which allows greater current to flow through the output diode, thereby increasing its switching speed. Pairs of photodiode circuits of the array are sequentially energized so that dual strings of outputs are produced. These outputs are then multiplexed and digitized. The digital outputs are compared in a verifier controller with a predetermined set of data to determine accuracy of the machining process. Substrates to be machined and verified can be mounted on a single X-Y table so that the machining and verification processes can be accomplished simultaneously.