Machining PEI CM ESD90 black

PEI CM ESD90 black is an electrostatically dissipative polyetherimide compression moulded (CM) into sheets. It combines the high stiffness, heat deflection temperature and inherent flame retardancy of PEI with a defined surface resistivity of approx. 10⁶ Ω – for components in ESD-protected areas of semiconductor and electronics manufacturing. PEI CM ESD90 black is an amorphous high-performance thermoplastic with high tensile strength and stiffness that are retained even at high temperatures (continuous service up to 170 °C). Conductive additives discharge electrostatic charges in a controlled manner; compression moulding produces a low-stress, isotropic structure and thus low-distortion machining even of large parts. Like all PEI grades, the material is inherently flame retardant (UL 94 V0) with very low smoke generation, resistant to hydrolysis and radiation, and absorbs little moisture. The colour is black due to the additives; amorphous materials are sensitive to stress cracking in contact with certain solvents.

PEI CM ESD90 black can be machined using all conventional cutting methods; sharp carbide tools and good cooling via chip removal avoid heat build-up and stress cracking. Cooling lubricants must be compatible with PEI. The compression-moulded sheets allow large-area and delicate machining with low distortion; for tight tolerances we recommend intermediate annealing.

PEI CM ESD90 black is used wherever heat-resistant, dimensionally stable components must safely discharge electrostatic charges – for example in semiconductor manufacturing, electronics and test and handling equipment.

• Wafer handling and test socket components
• Carriers, brackets and covers in ESD areas
• Insulating and functional parts with defined dissipation

PEI CM ESD90 black is calculated individually based on drawing or sample. The part price is determined mainly by the semi-finished form and dimensions, material utilisation and offcuts, machining effort and batch size. We are happy to provide binding prices on request.

The limits of the material are equally important:

• Sensitive to stress cracking with some solvents and cooling lubricants
• Lower toughness than PEEK
• Not generally declared for food contact (see FDA declaration)

An honest assessment:

• Advantage: Electrostatically dissipative (surface resistivity approx. 10⁶ Ω)
• Advantage: High stiffness and strength, even at high temperatures
• Advantage: Inherently flame retardant (UL 94 V0), low smoke density
• Advantage: Very low residual stress, high dimensional stability
• Disadvantage: Sensitive to stress cracking with some solvents and cooling lubricants
• Disadvantage: Lower toughness than PEEK
• Disadvantage: Not generally declared for food contact (see FDA declaration)