To understand the gravity of IPC-9191, one must first appreciate the problem it solves. In automated optical inspection (AOI) and surface mount technology (SMT) assembly, machines utilize computer vision to locate the PCB. However, the raw material of a PCB is rarely dimensionally perfect. Variations in the fabrication process, such as lamination shrinkage or etching irregularities, can cause the board to deviate slightly from its nominal dimensions.
IPC-9191 covers implementation at both the and process levels: ipc9191 pdf
ANSI Webstore : Offers the standard in Adobe Acrobat format. To understand the gravity of IPC-9191, one must