Yes: This application is a key factor creating a stable imaging operation. You need to determine exactly what data you want. Are you using step wedges to control your process and monitoring with a control chart? Do you want to chart the energy that the equipment is putting out or the energy that the resist receives? If you are looking at what the resist receives then you must include the photo tool. Photo tools add a very significant variation to the process. The data collection must be random. If you have exposure equipment where the lamp stays at full intensity while using a shutter to control millijoules and the shutter action is not affected by use (heat, lubrication) then the beginning of each shift is fine. If the lamp is instant on or reduced level and a less sophisticated shutter mechanism then data must be taken when the equipment has not been operated such as after shift change or lunch AND when the machine is hot such as after 85 exposures of a 100 exposure cycle. This could be part of the exposure variation. Guy Willingham ______________________________ Reply Separator _________________________________ Subject: FAB: SPC of printer Author: [log in to unmask] at corp Date: 9/26/96 7:07 AM TechNetters, here is another question about SPC. Is anyone using SPC at the board image printing operation? Our people here have been, at times and in an undisciplined way, been taking energy data from the printer. The gauge is put at 9 points in a grid and energy delivered thus measured. (These 9 measurements are made at approximately the same time, at the start of a shift, say.) To me, this approach seems to lend itself to SPC. Presumably, the measurements would be done on a regular schedule. Anyone care to comment or correspond? Lou Hart Quality Assurance Compunetics 412-858-6117 . *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************