Page 264 - Engineering Plastics Handbook

226 Engineering Plastics

have led to an increasing number of electronics and electrical applica-
tions. The polyimide is produced by Mitsui Chemicals, and cleanliness
is controlled during the polymerization without catalysts. The parts
that require cleanliness, such as parts inside of HDD and other drive
®
devices, have been feasible for polyimide. In addition, Aurum is increas-
ingly specified in silicon wafer and microprocessor handling, fabrication,
and testing operations for its unique combination of attributes:

1. High purity and low trace metal content
2. Low thermal outgassing at elevated temperatures
3. Dimensional stability at elevated temperatures
4. Surface resistivity control
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All-Aurum and Aurum –metal hybrid hard disk carriers provide excep-
tional dimensional stability at elevated temperatures (see Fig. 10.3).
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Aurum injection-molded liquid crystal display (LCD) glass carriers
can withstand LCD processing temperatures.
Ultrahigh-temperature (UHT) trays, called Olive, have been com-
mercialized by 3M. The material enabled its use in certain reflow appli-
cations, meeting JEDEC standards for flatness after multiple exposures
to 446°F (230°C).

Automotive. The rise in popularity of injection-molded polyimide and
seals within the automotive industry has been driven by the demand for
longer-life, extremely heat-resistant and ultrahigh-PV materials that
offer cost reduction opportunities over metallics and conventional poly-
imides. In vehicle locations including the transmission, engine, and

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Figure 10.3 Aurum –metal hybrid hard disk carriers.