Dry Film Developing Tests Fan Nozzles vs. Cone Nozzles in an Osc

Winter 1998

Dry Film Developing Tests Fan Nozzles vs. Cone Nozzles in an Oscillating Developer

The goal in developing a dry film image has always been to completely remove the resist from between the lines, especially where spaces are less than 5 mils (125 !lm), and to have a straight sidewall with no foot at the intersection of the resist and the surface to be etched. Whether this can be best accomplished by using cone nozzles or fan nozzle in a spray developer has been a topic of debate for many years. Three years ago Atotech, at the request of Hercules Inc., ran a series of tests in conjunction with Hercules to see if a difference in developing quality between the two nozzles could be detected. Two different flow rate fan nozzles were tested, both with and without oscillation, at three different breakpoints and compared to panels developed under the same conditions using cone nozzles. SEM micrographs showe Virtually no difference in complete removal of resist between lines or obtaining straight sidewalls with no foot between fans and cones run under similar conditions. Lower flow rate fan nozzles achieved the same results but at a slower conveyor speed and fan nozzles run without oscillation also achieved the same results at a slower conveyor speed.

Donald F. Ball, Atotech U.S.A.