To address the demanding high temperature processing needs of the electronics industry, 3M and Mitsui Chemicals have developed a unique, AURUM Thermoplastic Polyimide based formula for injection molded chip tray applications. Known as "Olive", this AURUM-based compound delivers an exceptional combination of thermal, electrical, and mechanical properties which enable its use in solder reflow applications and in other high temperature process carriers for the semiconductor industry and hard disk drive industry.

  In 1997, 3M's Electronic Handling & Protection Division was searching for a thermoplastic resin for injection molded, high temperature JEDEC chip carrier trays and a daunting list of performance and processing requirements was placed upon candidate materials.

  From a processing standpoint, the chip trays would need to be molded to an extremely tight flatness tolerance of < .030" while meeting thick (.480") or thin (.300") JEDEC profiles.

  In use, the trays would need to survive solder reflow temperatures as high as 240°C during such Ball Grid Array (BGA) assembly processes as C4 (Flip Chip) Die Attach, or Solder Ball Attach. The trays would also need to maintain their precise features and dimensions throughout thousands of reflow cycles. The trays would need to be static dissipative and have low thermal mass.

  Several high temperature resin candidates failed to meet 3M's flatness requirements when exposed to reflow temperatures. The AURUM-based "Olive" compound was selected as the ultra high temperature JEDEC chip tray material by satisfying all dimensional and performance requirements after repeated reflow cycling.

  According to John S. Burg of 3M's Electronics Handling and Protection Division, "Olive's cleanliness, dimensional stability, excellent electrical properties, and moldability permit its use across a wide range of high temperature applications." "Olive" exhibits low outgassing at elevated temperatures with outgassing data available upon request.

  A wide range of other injection molded AURUM handling devices and components for the electronics industry exist where high temperature stability and low thermal mass are required.

  (Indianapolis, IN) Borg Warner Automotive Turbo Systems has selected AURUM Thermoplastic Polyimide from Mitsui Chemicals (Purchase, NY) for two components in a new generation of viscous fan drives for the on-highway truck and agricultural vehicle markets. Borg Warner Automotive Turbo Systems' new, fully modulating drives control engine fan speed in direct proportion to engine cooling needs.

  In April of 1996, Borg Warner Automotive Turbo Systems commenced the development of a new line viscous fan drives featuring increased durability, longer operating life, and an expanded torque range of up to 1,000 lb in compared to earlier models.

  In previous models, a component called a fluid dam, whose function is to redirect silicone fluid from the drive to a reservoir, had been fabricated either as cast-in aluminum, stamped steel, or die cut Teflon. In operation, the dam is exposed to temperatures up to 350°F in silicone fluid, velocity of 4,500 ft/min, and maximum pressure of 100 psi.

  A second component called a valve system washer, whose function is to separate a bimetallic coil from the 380 aluminum drive cover while providing a low wear and friction surface, had also been die cut and formed from Teflon in earlier viscous fan drive models. The valve system washer is subject to a maximum temperature of 300°F in an unlubricated environment.

  Seeking a higher-performance and a cost-effective dam and spacer material, Borg Warner Automotive Turbo Systems initiated an evaluation of AURUM JCL 3030, an injection moldable polyimide known for its high strength and toughness, and resistance to creep and wear when exposed to high temperature and high PV conditions. Hilco Technologies (Grand Rapids, MI) a leading custom injection molder of high-temperature thermoplastics, was commissioned to perform the prototype molding of the initial AURUM dam and spacer test samples. Rigorous testing of the AURUM dam and washer samples was conducted including axial and torsional vibration testing, a 10,000 hour continuous bench endurance test, and a 1,500 hour accelerated engine and endurance test.

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  The test results showed that the AURUM dam and spacer met or exceeded all of Borg Warner Automotive's design goals. The insertable AURUM dam allows the fan drive cover casting to be used for all rotations whereas the cast in dams required one cover casting for each rotation. The molded AURUM dam holds firmly in the cover without the need for fasteners. The low friction and high strength properties of the AURUM valve system washer resulted in improved valve system performance.

  Late last year, the AURUM JCL 3030 dam and washer were specified for Borg Warner Automotive's new generation of viscous fan drives and in 1999 production molds have been constructed by Hilco Technologies. According to Joe Bloem, Plant Manager at Hilco Technologies, " AURUM's processing attributes such as low mold shrinkage, hot-runner capability, and rapid cycle times have resulted in very consistent, precision components for Borg Warner Automotive Turbosystems at a reasonable cost".

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  According to Borg Warner Automotive Turbo Systems, "AURUM JCL 3030 was selected for its exceptional combination of thermal resistance, dimensional stability at elevated temperature under load, wear resistance, and close tolerance injection molding capability". Borg Warner Automotive's new line of viscous fan drives will be launched during the 3rd quarter of 1999 and is expected to be used widely by the major worldwide large truck and agricultural vehicle manufacturers. Borg Warner AutomotiveTurbo Systems viscous fan drive assembly plant is located in Cadillac, Michigan.

  "The exceptional thermal and tribological properties of AURUM are derived from the polymer's high glass transition temperature of 482°F", according to Lee J. Hyde, Director of the Performance Polymers Division of Mitsui Chemicals America. Hyde cites extensive elevated temperature wear and friction data characterizing the outstanding tribological performance of AURUM. This testing was conducted using the ASTM D-3702 and JIS K-7218A thrust test methodologies.

  According to Hyde, the market for AURUM is comprised of (1) precision injection molded products covering the automotive, semiconductor, electrical and electronic, aerospace, and industrial markets and (2) extruded products including heat resistant tubing, wire and cable insulation, fiber, and stock shapes.

  Injection moldable, thermoplastic polyimides have been experiencing annual growth rates of 30 % or more with this growth driven by the demand for longer-life, extreme-heat resistant, high-purity, and ultra-high PV (pressure x velocity) materials offering cost reduction opportunities over metallics. Thermoplastic polyimides, manufactured by Mitsui Chemicals and marketed under the tradename AURUM, can be injection molded using conventional equipment and offer one of the highest Glass Transition Temperatures (Tg) of any commercially available, semi-crystalline thermoplastic at 482°F.

  The market for AURUM Thermoplastic Polyimide is comprised of 30% automotive, 30% electronics, 30% industrial, and 10% aircraft/aerospace applications.

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• Automotive/Transmission (Released 7/7/98)
• Automotive/Engine (Released 7/94)
• Automotive/Viscous Fan Drive (Released 6/99)
• Business Machinery/Copiers (Released 11/5/97)
• Business Machinery/Printers (Released 1/97)
• Industrial (Released 4/96)
• Aerospace (Released 3/95)
• Electronics/Chip Tray (Released 7/99)