INTELLIGEN LV DISPENSE SYSTEM
33
Installation and Use Manual | Entegris, Inc.
FLUSHING THE SYSTEM
Clean and flush the dispense system when the
chemical is changed, when the system is removed
from service for an extended period of time, or
when the dispense system and lines require flushing
to remove particulates.
WARNING! Wear chemical-resistant garments
and eye protection when working with all
chemicals.
The following procedure covers most photochemical
applications, but chemicals used for flushing and
cleaning must be compatible with the fluid in the
pump. Contact the photochemical fluid manufacturer
to verify that the flushing and cleaning chemicals used
will not adversely react with their product and will be
effective in flushing the pump.
Isopropyl alcohol (IPA) may react with the photo-
chemicals in the pump, so make sure that the pumps
and filters flushed with IPA are first flushed with the
photochemical base solvent before using photoresist
in the pump.
The amount of solvent, acetone and IPA used for
flushing are not fixed, but 500 – 750 mL is typical.
Depending upon the pump setup, the first 200 mL
of cleaning fluid can be recycled through the pump
to dissolve any residue. Remove and discard this fluid,
then pass fresh flushing chemical through the pump
and discard.
When changing photochemicals, the chemical
manufacturer may recommend a full tubing change
to avoid cross contamination. If the photochemical
solvent bases are the same, the acetone and IPA
flushes may not be necessary. Contact the photo-
chemical manufacturer for their recommended
procedure.
When flushing the pump to remove photoactive
compound (PAC) precipitates, contact the photo-
chemical manufacturer to determine the proper
solvent for dissolving the PAC crystals. In general,
the PAC crystals may not dissolve in a solvent base
and a stronger solvent such as N-methyl pyrrolidinone
(NMP) may be required. PAC crystals remaining in the
pump may act as nucleation sites and cause particu-
lates. Flushing of the pump is accomplished using the
Priming functions described in the Priming section
of this manual. In general, the rates entered when
flushing the pump can be higher than when priming
the system with chemical.
These settings will need to be adjusted for tubing
diameter, length, and the viscosity of the chemicals
in use.
Flushing a Working Pump
1. Remove the filter and replace it with a flushing shell.
2. Connect the inlet line to a photoresist solvent or a
manufacturer recommended stripper or thinner.
3. Follow the priming operation sequence to flush out
the pump, then continue to dispense until the bulk
of the original chemical is removed from the pump.
4. Connect the inlet line to a container of a manufac-
turer-recommended cleaning solvent.
5. Follow the priming operation sequence to flush out
the pump, then continue to dispense until the bulk
of the first cleaning agent is removed from the
pump.
6. Connect the inlet line to a container of isopropyl
alcohol (IPA) and flush the pump with this solution
to remove previous cleaning agents from the
pump.
7. Through the MMI, manually open all of the pump
valves. Also open the outlet valve.
8. Blow dry the pump using compressed and filtered
dry nitrogen. (A blow-down valve is available on
the prewet system. Turn the valve clockwise to
blowdown a pump.)
9. After 10 minutes, close the vent valve and continue
to blow-dry the pump for 10 minutes.
10. After 10 minutes, close the purge valve and open
the vent valve and continue to blow-dry the pump
for 10 minutes.
11. After 10 minutes re-open the purge valve and
let the dry nitrogen flow through the pump for
10 minutes.
12. Turn off the nitrogen blow-dry valve. Close all
pump valves.
