The PEEK™ telectronics market may be very broadly classified
into three key areas, namely: The production of semiconductor
materials, electrical and electronic applications (domestic and
business), and wire and cable production. The Polyaryletherketone
PEEK™ polymer is the material of choice for these applications
due to an unparalleled combination of physical properties, which
are subsequently discussed for application areas.
PEEK™ polymer is increasingly used for the transport and
storage of semiconductors during production. Historically. the
material of choice has been carbon fibre reinforced polypropylene.
However, with increasing specification of semiconductor wafers
it has become clear that polypropylene carriers have met their
limitation. Production is adversely affected by wear particles,
outgassing, doping of semiconductors by the ionic extractables
and poor mechanical properties of the carrier material.
Wear particles are produced by contact
between the carrier material and other surfaces.
Independent tests by industry experts have shown that PEEK™
polymer sheds extremely low levels of wear particles (ASTM-D-1044)
compared to other thermoplastics.
Outgassing may be defined as the
emission of volatile compounds, which may subsequently condense
on wafers causing contamination. The testing standard ASTM-Fl227-89
measures the Collective Volatile Condensed Material (CVCM) mass
at 20°C. Although PEEK™ polymer and polypropylene carriers
both meet SEMI specifications in this test, PEEK™ polymer
has a lower CVCM value. In addition PEEK™ polymer wafer
carriers have a tighter tolerance and retain their dimensional
stability over a much longer service-lifetime, or temperature
range (UL Continuous Use Temperature. CUT ~ 260°C). The excellent
mechanical properties of PEEK™ polymer over a wide temperature
range, increase the use of automated transfer production systems.
Semiconductor wafer carriers often
experience aggressive chemical environments at elevated temperatures.
Over a service-lifetime these materials may be leached of ionic
species, which have been shown to diffuse into the semiconductors,
acting as doping agents, PEEK™ polymer has extremely tow
levels of ionic extractables.
The electrical properties of the Polyaryletherketone PEEK™
polymer are typical of the generic class of thermoplastic materials.
However, the number and diversity of electrical and electronic
applications of PEEK™ polymer reflect the all-round high
performance of the material. Therefore, PEEK™ polymer may
form the insulating-housing for devices that operate in high-dose
radiation, chemically aggressive or high temperature environments.
The wire and cable coating industry is dependent on the processability
of polymeric materials and does not generally use high performance
thermoplastics. However, due to the ease of process and the high
quality of product. PEEK™ polymer is increasingly used in
demanding wire and cable applications.
Often, wires and cables used in potential
fire risk situations are insulated using PEEK™ polymer,
due to the outstandingly low values of flammability and smoke
emission for a thermoplastic material. Independent studies by
the Underwriters laboratory have shown that PEEK™ polymer
has a V-0 rating for a 1.45 mm thick sample white NBS smoke chamber
testing of a 3.20 mm thick sample shows no measurable emissions
after 4 minutes of ignition.
INSULATORS AND HOUSINGS
began using the Polyaryletherketone PEEK™ polymer to insulate
and house hermaphroditic electrical connection units for military
applications. Due to the outstanding success of the devices in
demanding mechanical and thermal situations, Lemo expanded the
use of PEEK™ polymer to form connectors, which feature in
devices for communications, medical, aerospace and research-instruments.
Although each of the individual specialist application areas requires
specific properties of the insulator material, a common feature,
which is key to many of these markets is the ability of PEEK™
polymer to retain a high degree of the electrical resistance and
mechanical strength close to the melting point of 343°C.
Spa is a major producer of electrical components such as switches,
connectors and relays. They have vast experience in the design
and manufacture of military devices and fully appreciate the demanding
requirements of this sector and the need for absolute reliability.
The Polyaryletherketone PEEK™
polymer was chosen to replace a polyamideimide material for a
particularly demanding connector system used by NATO forces in
the field (American Connector Standard MIL-0-26482). Although
both materials displayed sufficient mechanical and thermal properties
for this particular application, PEEK™ polymer exhibited
superior resistance to the chemical environments and the fatigue
loading encountered. Laboratory testing also showed that the 58
metal inserts which are added to the moulding after process are
more successfully retained in continuous 'application then removal'
experiments by PEEK™ polymer components. The use of the
Polyaryletherketone PEEK™ polymer for such devices also
removes the requirement of post-process annealing.
process of manufacturing semiconductors consists of more than
one hundred stages, during which hundreds of copies of an integrated
circuit are formed on a single wafer. Generally, the process involves
the formation of up to twenty layers of material on a semiconductor
The layering process creates areas of electrically active and
in-active material on the surface of the wafer. Due to the precision
and accuracy of these processes many of the stages are fully automated
and the wafers are transported in wafer carrier baskets.
Mitsui chose the Polyaryletherketone
PEEK™ polymer for carrier baskets, used in semiconductor
wafer fabrication as a replacement for fluoropolymer materials.
In addition to superior mechanical performance over a wide temperature
range, PEEK™ polymer offered lower levels of outgassing,
ionic extractables, wear particles and improved dimensional stability
which have been proved to be critical to the device yield.
AND CABLE INSULATION
extensive use of the Polyaryletherketone PEEK™ polymer as
insulation in the wire and cable industry is a testimony to the
ease of process and the physical properties of the material. Perhaps
the most demanding of these applications is the insulation of
reinforced cables used in the oil industry. BICC (UK) chose PEEK™
polymer for this application as they required a material, which
was electrically resistant and mechanically sound up to temperatures
in excess of 200°C.
The wires and cables used in mass
transit systems and commercial aircraft must have extremely tow
values of flammability and smoke emission to reduce the hazard
to passengers and crew in the event of a fire. PEEK™ polymer
is used as an insulating sheath in such applications as it has
been shown to be the safest practicable construction material.
Independent testing has shown that PEEK™ polymer has a UL94
rating of V-0 for a 1.45 mm thick sample whilst NBS smoke chamber
measurements show no appreciable smoke emission after 4 minutes