June 2000
Photo Resist Preclean in Three Minutes or Less
Precleaning various metal substrates in order to bond dry
film resists is always morc effective when scrubbing or
microetching to create a roughened surface. What this
does, in effect, is increase the surface area, which
increases film adhesion. This works well, providing the
change in surface appearance is acceptable to customers.
When it’s not’, then different cleaning methodologies must
be used and the resulting adhesion is lessened due (0 a
reduction in surface area. TIle trick is to be able to clean
all undesirable elements from me panel including oxides,
oils, fingerprints and the like, without redeposition; and
for those metals that require it, passivate to achieve a
smooth, oxide free surface conducive to good adhesion.
Many of these tocluliqucs require multiple alkaline baths
followed by acid pickles that can, in some cases, be very
lengthy processes.
James Taylor, Duratech Industries, Inc.
