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Browse Prior Art Database

Automatic Dispense Valve Closure Using an Electrical Solenoid

IP.com Disclosure Number: IPCOM000105844D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Chandler, WF: AUTHOR [+2]

Abstract

Described is a method to stop the flow of photoresist should a power off or loss of facilities occur. This can be incorporated into any photoresist coater or tool using a pneumatic pump system for dispense.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 73% of the total text.

Automatic Dispense Valve Closure Using an Electrical Solenoid

      Described is a method to stop the flow of photoresist should a
power off or loss of facilities occur.  This can be incorporated into
any photoresist coater or tool using a pneumatic pump system for
dispense.

      Install electric/pneumatic solenoid on dispense pump which will
drop out upon power failure.  This will allow air pressure through
the normally open port of the solenoid valve to close the dispense
port of the pump.

      To build an integrated circuit, the use of photosensitive
imaging film, called photoresist, is used.  The material is dispensed
from a tool called a photoresist coater.  During normal operation or
stand-by (power on), the dispense valve in the photoresist pump is
maintained in a closed position to prevent discharge of photoresist
to the waste container.  When the coater is powered off or loss of
facilities power occurs, the dispense valve automatically opens which
allows the contents of the resist reservoir to be discharged to the
waste container.  An additional problem that has resulted from this
occurrence is that the waste container has a one gallon capacity
while as much as 3 gallons could be discharged during loss of power.

      To solve the problem mentioned above, an electric solenoid was
installed on each of the 3 dispense pumps.  The normally open
solenoid valve is connected to the pneumatic port of the pump
dispense valve.  With power applied...