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.
