EMULSITONE COMPANY
19 Leslie Court
Whippany, New Jersey 07981
TEL. (973)386-0053
FAX (973)503-0256
SILICAFILM WITH BORON FOR THIN FILM HYBRID CIRCUITS
In addition to its use as a protective coating for monolithic integrated
circuits, Silicafilm with Boron is an ideal material for use as a passivating coating on
thin film circuits such as nichrome-gold films on glass or alumina substrates. The
particularly attractive features of the coating, in addition to its ease of application,
is the degree of impermeability of the film to water vapor and oxygen, thereby eliminating
the low reliability which nichrome resistors exhibit under load in high humidity
environments.
Application of the Film
1. The substrates need no exotic cleaning procedures. The substrates should be free of
grease or hydrocarbon contamination. Simple degreasing followed by a rinse in alcohol and
water is all that is necessary.
2. Silicafilm with Boron may be applied by spinning, dipping, or spraying. However, the
most uniform film thickness will be achieved by spinning. The following film thicknesses
will be observed for each of the various spin speeds:
| 3000 rpm | 1500 angstroms |
| 2000 rpm | 2000 angstroms |
| 1000 rpm | 2500 angstroms |
Silicafilm with Boron as delivered is free of particulate matter. However, if the bottle
is frequently opened, the accumulation of liquid on the mouth of the bottle and its
subsequent drying will yield glassy film-like particles which drop into the liquid and do
not dissolve. Should this occur, the material may be freed of this material by filtering
through a hypodermic syringe with a pvc filter holder and a membrane that is insoluble in
alcohol.
The quantity of solution applied to the substrate prior to the start of spinning must be
determined by experiment. In general, about 5 drops will adequately cover a 2 1/2" x
2 1/2" substrate.
The length of time of spinning will depend upon the spin speed. An adequate spinning time
can be determined by noting when the interference colors stop changing.
Heat Treatment
After spinning, the film should be baked. The criteria for the optimum temperature and
time for the bake cycle should be the maximum consistent with the allowable temperature
for the substrate. Silicafilm with Boron will harden on standing at room temperature.
However, the film will not exhibit its maximum hardness and density. Heating to higher
temperatures will yield a denser film. For the protection of nichrome resistors, heating
temperatures in the range of 250oC to 300oC for times of the order
of 1 hour are adequate.
| Alphabetic Product Listing | Home |
Material Safety Data Sheet |