Development of novel low-ohmic thin film resistors for TT Electronics plc.
Submitting InstitutionNorthumbria University Newcastle
Unit of AssessmentGeneral Engineering
Summary Impact TypeTechnological
Research Subject Area(s)
Engineering: Materials Engineering
Summary of the impact
This research within the Unit was in collaboration with TT Electronics
plc. to develop a novel low-ohmic thin film resistor for precision current
measurement in power management applications. TT Electronics plc. is an
international company with 6,000 employees worldwide and annual sales of
over £500 million to multinational clients such as BMW, Daimler and BAE
Systems. Since 2008 the benefits of this research to TT Electronics plc.
- a new product launched with a full scale new production line (4.8
million units per annum);
- confirmed new orders of £2 million over the next four years with 12
new international clients;
- 10% reduction in the production cost for existing thin film based
- an increase of employees by two per cent at Welwyn Components Ltd (TT
Electronics plc. plant in Bedlington, UK).
With increasing environmental awareness and ever-rising energy prices,
there is a growing market demand for the low-ohmic high precision
resistors in the range of 0.1-10 Ohms (2126). This is especially so for
portable devices for the purpose of saving battery power. For this type of
application, the more precise the resistor value, the more accurate the
current measurement in power management. Prior to this work there were no
suitable materials available to fulfil this requirement. Thick-film
resistors can cover an extremely wide resistance or ohmic range, but with
poor precision. Existing thin-film material systems, where the material is
vacuum deposited, offered the required precision but were not suitable to
manufacture resistors below 10 2126.
Since 1999, the Unit's academic staff, Dr Penlington (Principal Lecturer,
1994 - present) and Dr Birkett (Senior Lecturer since 2011) have been
working on the development of new electronic components (1, 2). These
activities resulted in the Unit being approached by TT Electronics plc. to
carry out research into the development of a new
copper-aluminium-molybdenum (CuAlMo) alloy with low resistivity. The
initial results obtained were encouraging and led to a successful grant
application (£72,500, The Royal Commission for the Exhibition of 1851:
Industrial Fellowship, 2006-2009). The research resulted in the
development of a new low-Ohmic alloy with a resistivity value of 80
µ2126cm and a temperature coefficient of resistance (TCR) of <15ppm/°C,
which could be used to manufacture thin-film resistors in the range of 100
m2126 -10 2126 (3-6). The main outcome of this research was the successful
integration of the low resistivity copper with the self-oxidising
properties of the aluminium to improve the material's stability. Finally,
in June 2008 a small quantity of molybdenum was added to the system to
control the TCR level and further improve the material's stability. Having
developed the film material the research moved on to optimise its
composition for full scale production of a new range of surface mount
current sensing resistors at TT Electronics plc. in 2010.
References to the research
1. Putrus, G. A., Ahmed, M. M. R., Ran, L., Xiao, L., Penlington, R., and
May, S. (2001) `Hybrid fault current limiting & interrupting device',
Northumbria & Northern Electric Distribution Ltd, Patent No. GB2375902
2. Ahmed, M. M. R, Putrus, G. A., Ran, L., and Penlington, R. (2006)
`Development of a prototype solid-state fault-current limiting and
interrupting device', IEEE Transactions on Power Delivery, 21
(4), pp1997-2005. DOI: 10.1109/TPWRD.2006.874584
3. Birkett, M., Brooker, J., Penlington, R., Wilson, A., and Tan K.
(2008) `Electrical characterisation of AlCuMo thin films prepared by DC
magnetron sputtering', IET Science, Measurement and Technology, 2
(5), 304-309. DOI: 10.1049/iet-smt:20070076
4. *Birkett, M. & Penlington, R (2012) `Laser Trimming of CuAlMo Thin
Film Resistors: Effect of Laser Processing Parameters', Journal of
Electronic Materials, 41 (8), pp2169-2177. DOI:
5. *Birkett, M., and Penlington, R. (2012) `Laser trim pattern modelling
and optimisation for CuAlMo thin film resistors', IEEE Transactions on
Components, Packaging and Manufacturing Technology, 3 (3),
pp523-529. DOI: 10.1109/TCPMT.2012.2223468
6. *Birkett, M., Penlington, R., Wan, C., and Zoppi, G. (2013)
`Structural and electrical properties of CuAlMo thin films prepared by
magnetron sputtering', Thin Solid Films, 540, pp235-241.
* denotes the references that best indicate the quality of the
The research was supported by a grant from the Royal Commission for the
Exhibition of 1851 (Industrial Fellowship of £72,500 for the period of
2006-2009, PI- Dr. R. Penlington).
Details of the impact
TT Electronics plc. is a global electronics company supplying the world's
leading manufacturers in the automotive, defence, aerospace,
telecommunications, computing and industrial electronics markets. They
have average annual sales of over £500 million and employ over 6,000
people worldwide at manufacturing, engineering and sales support
facilities in North America, Europe, the UK, Mexico, Barbados, Malaysia,
Japan, Singapore, Hong Kong, India and China, with sales to major OEMs
including BMW, MAN Trucks, Daimler, BAE Systems, Selex, Smiths detection,
Thales, Boeing, Airbus, Schneider, Hager, Philips Medical and GE Medical.
The outcome of the Unit's research is the novel CuAlMo alloy film
material. This has had the following economic and commercial impacts for
TT Electronics plc.:
- Launched a full scale production in January 2010 (4.8 million units
per year) and satisfied market needs for the precision low current
measurement in power management applications with a large number of
clients across the globe.
- Invested £750,000 in a new production line in 2007 to manufacture 4.8
million resistors per year, which in turn generated new production jobs.
- Created new full time jobs for the new production facility, in
September 2009, thus increasing the number of employees by 2% at Welwyn
Components Ltd. (TT Electronics plc. plant in Bedlington, UK).
- Increased the competitiveness in a new electronic component market
(since 2010 till present) and won additional contracts with 12 new
clients in the power management market sector, estimated to be worth £2
million over the next four years.
- Incorporated the newly developed material into the manufacturing of
existing resistor products (24 million units per year) in March 2010,
which reduced the production costs by 10%; through savings in resources
such as equipment, power and material consumption and labour. The
additional income generated as a result of using the new material for
the production of existing resistors is currently at £120,000 per annum
- Reduced the number of vacuum deposition machines from five to two in
November 2010, which led to a significant reduction in corresponding
overhead costs related to the electricity and gas consumption and the
maintenance by 60%. Since the developed thin film is also thinner, it is
therefore easier to cut through at the subsequent laser trimming stages,
which in turn has reduced the time from production to the market
This impact is corroborated in the following statement from the Global
Product Line Director at TT Electronics plc.:
"The development of this new low resistivity thin film resistor
material has been of significant benefit to TT electronics. The research
collaboration between Northumbria University and TT electronics focussed
on the development of a new precision resistor material which is used to
satisfy a gap in the global market for precision current measurement in
power management applications.
The end result of the research was in the form of a material
composition of CuAlMo which not only satisfied this requirement but also
allowed a wider range of resistor values to be manufactured at lower
costs, providing savings in material, labour and overheads. This work
has also been instrumental in the setting up of a new £750K surface
mount thin film chip resistor production line at TT Electronics plc.
This line now produces around 5 million resistors per annum and has
created new jobs for full time production operators.
In summary the research work of a group of academics at Northumbria
University on the development of a new precision current sense resistor
material has been vitally beneficial for TT Electronics commercial
activities in targeting a new growing market and generating new business
and also in reducing cost of production of existing products."
Sources to corroborate the impact
Reports, reviews and web links or other documented sources in the
Information on TT Electronics plc. http://www.ttelectronics.com
Low-ohmic Product Specification Sheet:
The following web link illustrates the link between Dr Martin Birkett and
his research with TT Electronics plc.
Emerald Publishing (2007) `Promotion for Electronics Talent', Microelectronics
International, 24 (2)
The following web link reports on the development of the film for Welwyn
Components Ltd. (TT Electronics plc.'s plant in Bedlington, UK).
Bush, S (2009) `Copper-based Metallic Film Improves 0R1 to 10R Chip
Resistors', Electronics Weekly
Individual users/beneficiaries who can be contacted to corroborate claims
The Global Product Line Director for TT Electronics plc. has provided a
statement and can corroborate all of the impacts claimed in this case