EV Group EVG620 mask aligner

Where a used EVG620 fits

The EV Group EVG620 is a mask aligner for wafers and pieces up to 150 mm, with recipe-driven exposure and, on many units, bottom-side alignment. It is a common choice for MEMS and microfluidics groups that need double-sided alignment and repeatable thick-resist exposure, and for pilot lines that want less operator dependence than a fully manual aligner.

Depending on configuration, the same frame was also sold with bond alignment tooling and with UV nanoimprint options, so two used EVG620s can be very different tools. The 200 mm version is the EVG6200; if your roadmap includes 200 mm, look at that rather than converting a 620.

What we check on inspection

The EVG620 combines optics, pneumatics and a PC, and each needs checking:

• Control PC and software: boot, recipe storage, licences and a full backup before anything else is touched.
• Exposure system: lamp hours, intensity, uniformity and the shutter timing at the wafer plane.
• Wedge compensation and contact: how evenly the wafer meets the mask in each contact mode.
• Alignment stage: motor and encoder function, backlash and repeatability.
• Bottom-side alignment: camera optics, image capture and the stored alignment offsets.
• Pneumatics and vacuum: valves, regulators, tubing and chuck vacuum.

We expose a test mask to confirm the tool runs end to end, and the report lists the tooling that comes with it.

Refurbishment scope

Typical refurbishment covers worn pneumatic parts and seals, cleaning and realignment of the exposure optics, calibration of the intensity sensor, stage adjustment and a software backup on new storage. Where the PC is failing, we move the software to replacement hardware as part of a control system retrofit. Certified units are run on a test exposure with overlay results in the report.

Upgrades and spare parts

A UV-LED source removes lamp changes and warm-up, and suits labs that run the aligner in short bookings. We also add chucks and holders for pieces, rebuild bottom-side alignment tooling that has gone missing and supply lamps, seals and pneumatic parts. We are independent of EV Group and state the origin of every part we fit.

Facilities

• Mains power for the aligner, PC and lamp power supply (depending on configuration)
• Vacuum for chuck and mask holder
• Clean dry air for pneumatics and nitrogen for contact modes
• Exhaust for the lamp house with a mercury lamp fitted
• Stable floor or isolation table in a yellow-light area

Buying advice

Ask which modules are actually installed and working: bottom-side alignment, bond alignment, nanoimprint. Ask for the software version and whether the recipe files are included. A unit with a healthy PC and complete tooling saves weeks of work.

On a site visit, ask the seller to load a mask and wafer and run one exposure in each contact mode you plan to use. Watch the wedge compensation and separation. A hesitant stage, vacuum alarms or a sequence that stops partway usually point to pneumatic leaks, worn valves or control faults. These are repairable, but price them before you commit. Note the lamp type and hours, and when the intensity sensor was last calibrated.

Compare it with the SUSS MA6 and read our used mask aligner checklist before a site visit. The lithography overview covers the rest of the category.