Chemical Dispensing System
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
This chemical dispensing system has the benefits of 1) filtration of the chemical very close to the point of use, 2) degassification of the chemical just prior to application, and 3) droplet elimination after dispensing by means of a simple pull-back valve. There are no metal valves in the system nor any rubbing parts to produce particles. The system is particularly well suited for applying chemicals in spin coating applications. The diagram shows the supply cylinder 2 which contains the chemical to be dispensed in a reusable liner. Tubing 4 is used to supply nitrogen pressure during the dispense cycle and to provide a slight vacuum between dispense cycles. Any gas in the chemical is thus removed prior to dispensing. A submicron filter 6 is installed downstream of the cartridge 2.