Customised VCAP Planar Voice Coil Actuator XY Module for Wafer Probe Stations

Product Overview

The VCAP-XY module is a dual-axis planar actuator module comprising a pair of flat voice-coil drivers mounted vertically on a common base, with cross-roller guides and linear encoders integrated as standard. This product is offered as a customisable platform: peak thrust ranges from 20 N to 100 N per axis, with stroke ranges from 1 mm to 20 mm per axis. Rather than having to purchase two actuators and design a mechanical structure around them, customers receive a pair of matched components that have already been aligned, characterised and tested as a single unit, thereby reducing the integration cycle for new instruments from months to weeks.

Solution

Planar X-Y motion in semiconductor and metrology equipment is typically based on stacked ball screw stages or linear motor gantries. Whilst both approaches are viable, ball screw stages introduce friction and wear into clean environments, whilst gantries require significant space around the working area.
Voice-coil X-Y modules not only keep moving mass to a minimum but also eliminate all transmission components from the motion path, allowing them to be mounted directly beneath chucks, probe cards or optical heads. As each axis acts as a force source, the controller can switch between position mode during scanning and force mode during probe testing or contact measurement without any hardware modifications.
The short travel is not a limitation but rather an advantage: whether inspecting a 10-millimetre field of view or stepping a probe card across a chip, the axes need only move a few millimetres; the lightweight, direct-drive axes can complete this movement within milliseconds, with stability and accuracy at the sub-micrometre level. Cable management, mechanical stops and encoder scales are all included in the delivered module, so customers need only integrate a mechanical interface and a connector, rather than designing a platform from scratch.

Specifications

Application

Wafer probing and die stepping, optical inspection with a small field of view, precision measurement and profilometry, micro assembly of optical and electronic components, laser micro processing with a small working field, and laboratory instruments that need a compact two axis positioning platform inside a confined enclosure.

FAQ

Q: Can the two axes use different force ratings?
A: Yes. Mixed combinations are common, for example a 100 N axis carrying the load and a 20 N axis doing fine correction. The module is quoted around the required force, travel and settling time for each direction.

Q: Is the module supplied with a controller?
A: It can be. We quote actuator only, module with encoders, or a complete package including two servo drives and a motion controller with the application loop already tuned.

Q: How is orthogonality verified?
A: The base plate is machined in one setup and the guides are aligned against a granite reference before bolting, so orthogonality is measured at the factory and reported on the inspection sheet supplied with the module.

Q: What is the typical delivery time for a customized module?
A: Around 4 to 6 weeks after drawing approval. Standard 20 N and 30 N combinations ship from stock components in 2 to 3 weeks.

Q: Can it run in a vacuum chamber?
A: A vacuum compatible version is available with dry lubricant guides and low outgassing cable, which is typical for electron beam and ion beam instruments.

Ordering Information

To quote an assembly we need the required thrust per axis, travel, load mass, settling time, encoder resolution and the available envelope. Drawings are returned for approval before machining.