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Processing Procedures for Holographic Photoresist Plates |
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STORAGE OF UNEXPOSED PLATES
Unexposed plates should be stored in light proof boxes at 70ºF (21ºC) at 40 to 45% relative humidity. Plates stored in this manner should remain good for a minimum of 6 months.
EXPOSURE
Exposure varies with both the equipment and layout. Specific exposure time is usually determined by a trial and error method.
The 3 most common lasers for exposing photoresist plates are:
Krypton (413nm)
Helium-Cadmium (441nm)
Argon (457nm)
DEVELOPMENT
Develop using Shipley 303 developer mixed 5 parts distilled (or de-ionized) water to 1 part developer.
Place the plate in a tray of developer, and agitate constantly for 7 to 10 seconds. Remove the plate and rinse immediately with DI Water using a low power spray nozzle to stop developing. Continue to rinse in the same manner for about 2 minutes.
Experienced holographers will experiment with developer concentration and developing time to achieve varying results.
DRYING
Dry the plate quickly and completely to avoid water spots. The best method is to blow the plate dry with a high pressure stream of compressed Nitrogen. Dry, filtered, compressed air will work as a second choice.
STORAGE OF FINISHED PLATES
Developed plates are still sensitive to light. They should be stored in light proof boxes. Inspection time under white light should be kept to a minimum.
ADDITIONAL INFORMATION
Some additional exposure information from Shipley Corperation can be found here.