Royenface - Maskless electrochemical patterning
| Assignment title: | Maskless electrochemical patterning |
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| Start date: | October 2010 | |
| Client: | Royenface Limited | |
| Investigator | Dr David Nugent david.nugent@elucidare.co.uk |
Introduction
Royenface Limited is a spinout from Newcastle University and the microfabrication laboratory of Professor Sudipta Roy. The company aims to exploit its newly patented electrochemical patterning technology within the microelectronics industry. Elucidare has guided Newcastle University towards the creation of Royenface since August 2007. Upon its incorporation in October 2010, Dr David Nugent, Elucidare CEO, joined Royenface as Director of Business Development.
Technology
The Enface technique allows metals to be patterned without the need for a photomask and photoresist. In this process, metals are selectively etched from or deposited onto a surface (the substrate) by replicating a pattern present on a pre-fabricated and reusable template (the tool).
The Enface process is illustrated below. The substrate (dark blue) and tool (dark red) are immersed in an electrolyte, and then positioned flush in close proximity to one another. Deposition and etching result from the passage of current through the electrolyte between substrate and tool, both of which are acting as electrodes in the process. If the substrate is connected to the negative terminal of a power supply (cathode) deposition takes places (b"). Alternatively, if the substrate is connected to the positive terminal (anode), etching takes place (b').
The above figure shows the following unique features of Enface technology:
First, it allows the metals to be deposited and etched in a well-defined pattern without having to resort to masking parts of the substrate. Herein lies the key benefit of the Enface process: it is a single step process representing significant cost and time saving over conventional pattern deposition and etching methods.
Second, the Enface process uses solutions with very low concentrations of metal salts. This reduces operating costs for component manufacture, especially when precious (i.e. palladium, gold, silver) or strategic metals (such as nickel and copper) are used. The use of novel and specialised chemistry is retained by Royenface as undisclosed IP (know-how) and provides additional scope to link up with chemical suppliers to develop new products which can provide additional royalties.
Third, the process consumes little electrical power because it operates at room temperature and the inter-electrode gap is small. Enface can be employed in a standard well-equipped laboratory space, i.e. clean room conditions are not required.
Advantages
The Enface processes addresses the most pressing technological and financial challenges confronting the microelectronics packaging industry today. Individually any one of these solutions would be commercially desirable; collectively they provide a complete solution to enable component manufacturers to increase profitability and productivity, improve device performance and reliability, and reduce environmental damage and decontamination costs.
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End market trend |
Leadframe application |
Royenface solution |
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Precious metal prices at all-time highs |
Operating margins under pressure Industry seeking novel patterning techniques |
Significantly reduced precious metal consumption |
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Faster CMOS speeds require finer leadframe geometries |
Conventional masking techniques are incompatible with fine leadframe geometries | ENFACE is a non-contact deposition process and therefore should not disturb leadframe structures |
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Trend towards low-cost plastic encapsulants |
Plastic moulding components do not bond well with NiPdAu causing premature device failure | Proprietary techniques for selective plating and surface roughening |
| Component manufacturers under pressure to reduce chemical consumptions | Leadframe producers amongst largest users of de-ionized water in the world | Significantly reduced chemical wastage and cleanup costs |
| Higher brightness and LEDs and faster microprocessors generate more waste heat | Leadframe produces are seeking novel methods of improving thermal transfer through the substrate | Selective copper deposition can be used to enhance thermal heat sinking through substrate |
Applications
The Enface process reduces costs, increases productivity and enhances device performance in a wide range of microelectronics packaging applications including leadframe patterning and selective surface roughening, ball grid arrays (BGAs), through silicon vias (TSV) etc.
Documents available for download
| US Patent: Process for Manufacturing Micro- and Nano- Devices |
Click here