Page 78 - PCMI Journal December 2020

General Overview of PCM Equipment - Wet Processing Presented by: Mike Soble, Technical Sales Manager, Chemcut Corporation, US
11/23/20
46
MEDIUM STRIP:
The Key Parameters for MEDIUM STRIP machines are:
Ø DWELL TIME / CONVEYOR SPEED:
• Dwell time is typically 80 to 120 seconds in a spraying chamber.
Ø TEMPERATURE CONTROL:
• STRIP stations have both heating and cooling elements. As the rate of chemical reaction increases
with temperature, it is important that the temperature be maintained at the desired temperature for consistent Stripping
Ø MANUAL PRESSURE CONTROL:
• Uses valves and pressure gauges to adjust upper and lower spray pressures
Ø BATH MANAGEMENT:
• STRIP systems can be operated as a batch process. Consistent chemistry replacement based on specified time or based on the number of panels processed is necessary to achieve consistent Stripping.
• FEED and BLEED systems based on panel count are provided to keep the bath refreshed with chemistry
Chemcut
45
MEDIUM STRIP:
The Key Parameters for MEDIUM STRIP
machines are:
Ø FILTRATION OF RESIST CHIPS
Dry-film photo-resists in Stripping chemistry are designed to Strip off panels in a small flakes or “CHIPs”. These Resist Chips can then be filtered and removed from the bath by mechanical means. The removal of the chips in this fashion increases the bath life and minimizes the solids content of the bath to avoid spray nozzle clogging and excessive particulate settling in the chamber creating a sediment layer on the
bottom of the Strip chamber.
Chemcut
Issue 136 December 2020 PCMI Journal 7283