Equipment

MiniFAB has installed a wide selection of specialised equipment in Class 10,000 and Class 1000 cleanrooms that enable us to provide a unique and comprehensive service to our clients. Below are details of the systems routinely used to make micro and nano scale features in range of engineering materials. If the equipment you require doesn’t appear in this list please contact us to discuss your application.

Laser Micromachining

Excimer Laser

MiniFAB operates two excimer laser systems working at a wavelength of 248nm or 193nm. These lasers provide nanosecond long pulses of intense UV light that can etch polymeric materials without causing thermal damage. Features as small as 1µm in width can be machined and the depth of features can be controlled to <<1µm. These lasers are also ideal for patterning thin (<2µm) films on a variety of substrates. MiniFAB has extensive experience in cutting and patterning a vast array of features and materials using this type of laser.

Frequency Tripled YAG laser (AVIA)

A pulsed UV laser system (wavelength = 355nm) combined with a galvo scanner system that allows cutting of a wide range of polymers, metal films and foils, ceramics, semiconductors, adhesives and other materials. Typical cut widths from ~20µm are possible and the cut path is controlled by a CAD defined tool path.

Lithography

Lithography Suite

MiniFAB’s lithography suite is supported by an array of auxiliary equipment required for wafer processing and measurement of the micro-features. Hot plates, wet-chemistry benches, metallisation processes (sputtering and electroforming) and microscopy are available in house.

Spinner

Deposition of uniform, thin layers of material are made by spinning parts at high speed before dispensing controlled volumes of solutions or material suspensions. Adhesives and photoresists are the most common materials applied using this method. Typical film thicknesses can range from ~1µm to several hundred microns.

Mask Aligners

MiniFAB operates a suite of mask aligners for the UV patterning of photoresist layers on a variety of substrate materials. Features as small as 2µm in width can be exposed before wet chemical processes are used to develop the resist structures. The photoresist moulds can then be used in etching or metal deposition processes. This equipment is designed around 4” and 6” silicon wafer platforms.

Nano Imprint Lithography

NIL is a relatively new lithographic process that enables features <<1µm in size to be replicated in thin photoresist materials. Subsequent processing can then transfer the photoresist structures into the substrate material or replicate them in metal using electroforming.

Micro-milling

Direct milling of micro-features into a variety of polymer materials is a key process capability for MiniFAB. Tooling down to 50µm diameter is routinely used to directly fabricate parts or to create tooling for use in subsequent processes.

Metallisation & Electroforming

Magnetron Sputtering

DC magnetron sputtering is used by MiniFAB to deposit thin metal films (typically copper, chromium, titanium and gold) onto a variety of substrate materials including polymers and silicon. Film thickness from a few 10’s of nanometers to ~1 um can be deposited with controlled adhesion properties.

Large Format Electroforming System

Electroforming a metal tool up to 1m x 1m in size from a polymer or metal mould containing micro-features can be performed by MiniFAB. Metal shims made in nickel can be fabricated with a thickness from 100 to 500 um. This state of the art electroforming system creates nickel shims with well characterised hardness and a total thickness variation (TTV) < 10%. This process yields robust metal parts that replicate complex micro-features produced by other fabrications processes. Features <<1µm can be routinely reproduced in the electroformed parts.

Polymer Replication

Injection Moulding

A Class 10,000 clean room based electric injection moulding system with 60 tonne clamping force is used by MiniFAB to produce moderate to high volumes of polymer parts. The 25g maximum shot size can form parts with dimensional tolerances of the order of 1µm in a range of polymer materials (ie PC, COC, PP, etc)

Hot embossing

Hot embossing of microstructures into polymer parts can accurately reproduce features <1µm in width. Accurate alignment of parts to embossing tools can also be achieved using optical alignment tools. MiniFAB can use hot embossing processes for low volume proof of principle production runs for validation and testing.

Conformal Coatings

Parylene Coating

Parylene coating is method by which MiniFAB can apply a transparent, conformal polymer coating to a surface to improve chemical resistance or biocompatibility. If required, surfaces can be pre-conditioned (plasma etch) to improve adhesion of the defect free parylene coating and thickness can be controlled from a few microns to several tens of microns. Parylene C is the most common form of this material and other dimers, such a Parylene N can be used to provide specific solutions if required.

Wire Bonding

Die Bonding

Placement of die’s or other small components onto circuit boards (PCB, flexible circuit boards, hybrids, silicon substrates, etc) with very high positional accuracy (~5µm) can be performed by MiniFAB using a semi-automated pick-and-place process. Adhesives will be selected on case by case basis depending on requirements.

Wire Bonding

Integration of electronic components into circuits can be realised by connecting bond pads as small as 50µm in diameter using 25 µm aluminium or gold wire. MiniFAB can produce ball or wedge bonding on single interconnects or high density packages.

Pull Testing

Pull Testing is a non-destructive QC method for testing the quality of the connection made during the wire-bonding process. The method works by applying a calibrated force to the wire to determine if the bond fails.

Metrology & Testing

Microscopy

Optical, scanning electron and laser scanning confocal microscopes are essential tools in the characterisation and quality control aspects of MiniFAB. These microscopes enable calibrated measurements to ~ 1µm resolution.

Surface profilometry

An optical surface profilometer is routinely used in our development and fabrication processes for QC measurement of structures from around 1µm in length.

Custom testing

MiniFAB can provide custom testing and characterisation methods for a broad range of micro-fabrication related applications. Enquires into new and novel applications are encouraged.

MiniChemLab

A large proportion of MiniFAB’s work involves the fabrication and testing of microfluidic devices. MiniChemLab is a microfluidic workstation developed by MiniFAB in order to quickly drop in fluidic cartridges and test performance. MiniChemLab can be integrated with a number of different sensor technologies that would benefit testing of microfluidic devices.