ASML 879-0262-002 Shutter

The ASML 879-0262-002 is a high-speed optical shutter assembly designed for precise beam interruption in lithography systems. This shutter provides fast, repeatable switching of the illumination beam, enabling exposure dose control and safety interlocks. Its robust construction and low-vibration operation make it suitable for integration into PAS and TWINSCAN steppers.

Technical Specifications

• Part Number: 879-0262-002

• Type: Electromechanical beam shutter

• Aperture Diameter: 25 mm

• Opening Time: < 5 ms

• Closing Time: < 3 ms

• Actuator: Voice coil with position feedback

• Control Signal: 24 V DC, 0.5 A (coil drive)

• Position Sensor: Hall effect, open-collector output

• Operating Temperature: 10°C–40°C

• Mounting: 4 x M3 threaded holes on 60 mm x 30 mm pattern

• Material: Aluminum housing with black anodized finish

Functional Description

The shutter uses a rotary voice-coil actuator to move a low-inertia blade across the optical aperture. The blade is designed to minimize beam scattering and thermal distortion. The position sensor provides a confirmation signal to the controller, ensuring that the shutter state (open/closed) is known at all times. A built-in spring return ensures fail-safe closure in the event of power loss.

Installation and Mounting

Mount the shutter on a rigid optical support using the four M3 screws. Ensure the aperture is centered on the beam path; use a visible laser to align. Connect the control cable to the stepper’s shutter driver module – the cable has a D-sub 9 connector with pin assignments defined in the manual. The power supply for the coil must be capable of providing 0.5 A at 24 V with a 10% duty cycle (for intermittent operation).

Control and Timing

The shutter is controlled by a TTL-compatible signal: logic high opens the shutter, logic low closes it. The opening and closing times are measured from the signal edge to the position sensor change. For precision dose control, the shutter can be modulated at frequencies up to 50 Hz. The controller can also monitor the sensor signal to detect faults such as blade sticking or slow response.

Maintenance and Reliability

The shutter has no wear parts except for the blade pivot bearing, which is lubricated for life. Routine inspection includes checking the blade for any deformation and verifying the operation with a test signal. The MTBF is estimated at 500,000 cycles. If the shutter becomes sluggish, the coil resistance can be checked (nominal 48 Ω). Replacement is recommended if the opening time exceeds 6 ms.

Integration with Stepper Systems

This shutter is compatible with ASML PAS 5000/2500 and TWINSCAN exposure systems. It interfaces with the dose control board, which sends the open/close commands based on the required exposure energy. The shutter can also be used as a safety interlock to block the beam when the operator opens the chamber door.

Environmental and Safety

RoHS compliant and CE marked. The shutter is a Class 1 laser product when integrated. It should be operated in a clean, dry environment. The housing is grounded to dissipate electrostatic charges.

Technical Support and Documentation

ASML provides a detailed data sheet, timing diagrams, and installation instructions. Replacement blades and coils are available. For critical applications, a spare shutter unit is recommended.

Conclusion

The ASML 879-0262-002 Shutter offers fast, reliable, and precise beam control for advanced lithography. Its robust design and fail-safe features ensure safe and consistent exposure performance.