Talk of LED lighting applications was once guaranteed to send any self-respecting semiconductor distributor to sleep. Not any more.
A combination of advances in semiconductor LED technology, the cost benefits of semiconductor production and ever-present environmental concerns have all contributed to the new phenomenon which is LED lighting.
The commercial potential of the lighting market is only as big as the vast range of end products and customers it addresses. This adds a new sales approach for traditional semiconductor distributors.
According to David Spragg, technical and marketing director at Arrow UK, the LED market consists both of the traditional industrial electronics customer base and non-traditional customers, who may not have purchased electronic components or have bought only in very small quantities.
“The ‘new’ customers range from industrial lighting specialists to architectural lighting designers. Whilst all require technical guidance, at the latter end of the spectrum this support is in greater demand,” says Spragg.
The architectural designer is new to the distributor. Unlike the more traditional industrial LED user, architectural designers differentiate themselves by using state of the art products, and consequently need to be constantly updated with new products and technologies.
“Architectural lighting designers see light aesthetically rather than functionally, so their decisions are much more subjective,” says Mike Hall, opto product specialist, Abacus. “Two customers will see a project in two completely different ways. You therefore need more than one solution to address both the specification and the artistic requirements of the design.”
According to Stephen Morris, applications manager for EBV, as the LED lighting business grows the distributor has a role to play providing design and component technology information.
“The prime requirement here is to have application engineers with the distributors. They will try out suitable types of LEDs and will decide on the ideal form of actuation for the specific application,” says Morris.
“Most electronic design-ins are based on performance in some form or other, so discussions start from a data sheet with possible reference to a price list. This is in sharp contrast to industrial designers, who tend to prefer proven established technologies that are normally also more cost-effective,” adds Abacus’s Hall.
Another difference, reckons Hall, is that architectural designers will need advice on how to drive and thermally manage LED designs.
For example, an architectural LED may work wonderfully for 10,000 hours but disappoint after 20,000. “Customers need to understand the trade-off between drive current, thermal management and lifetime,” says Hall.
“Whereas LEDs were previously ruled out because they were too expensive and their efficiency was inadequate, they are now an extremely attractive alternative. They are primarily useful wherever long service life and a high level of efficiency are required,” says Morris from EBV.
According to Steve Rawlins, CEO at Anglia, it is important for the designer to remember that the design of LED lighting assemblies involves much more than just the LED emitters themselves.
“The complete system involves an aluminium clad PCB to aid heatflow away from the devices, and often also a larger metal heatsink. Drive circuitry is very important, not just the AC-DC constant current source but also the interface with a microcontroller,” says Rawlins.
Architectural light designs also need to be looked at from an installation point of view, as well as design on the PCB. Usually, a third party installer will fit the electrics, and they will not be electronics technicians.
“For the last architectural LED contract we secured, the final meeting was in a room containing 12 different people from five different disciplines, each of which had an input into the lighting fixtures to be used,” says David Moorhouse, sales and marketing director at LED supplier, Marl International.
This can be a new decision making process for the distributor.
“For a large project, the client who is paying for the building will be advised by a lead architect or consultant. They may involve consulting architects as well as specialist mechanical, electrical and civil consulting engineers, and a quantity surveyor or cost consultant,” says Moorhouse. “The occupier of the building, who may or may not also be the client, will involve their facilities management, health and safety and personnel departments.”
Some lighting projects can go out to tender. “The actual lighting may then be installed by a subcontractor who will have an account with an electrical wholesaler. That’s who you need to supply the product to,” adds Moorhouse.
Marl addresses the architectural lighting market via its lighting distributor Architectural FX and Foremost Components which supplies the man machine interface components.
So why is the electronics supply chain getting so excited by the LED market?
“There are several factors fuelling the fast growth in LED lighting. These may be environmental – related to energy efficiency; technological – based on what effects can be achieved with new alternatives to incandescent sources; or economic – related to reliability and maintenance costs,” says Arrow’s Spragg.
“What is causing the current upsurge in interest from all those involved, including distributors, is that technological advances have brought us to a tipping point in many applications where new lighting sources are becoming viable alternatives to traditional solutions,” adds Spragg.
Batch process in LED production
LEDs are not off-the-shelf products, especially when they are intended for use in automotive.“LEDs are produced with different kinds of brightness and hues,” says Martin Hetz, product marketing manager at Rutronik.
“The use of different manufacturing technologies and material compositions can only influence brightness and hue to a certain extent so that, at the end of a production batch, a broad range of different kinds of brightness and hues is nonetheless produced.”
“To be able to use LEDs so that the human eye perceives homogenous illumination conditions in the application, the greatest possible match in terms of the brightness and hue of the LEDs used is essential, so the LEDs produced have to be divided into so-called half-groups,” continues Hetz.
The basis for the colour co-ordinates is the internationally recognised CIE chromaticity diagram.
“Automobile manufacturers normally issue a specification to their suppliers, which stipulates precisely the brightness in cd/m sq. and the hue of the light on the surface in the application,” explains Hetz. “To comply with this specification, it would be helpful for the automotive supplier to use only one brightness half-group. As, for the reasons described, this cannot be guaranteed, th e supplier must work with different multipliers or electrical control systems, so that the same brightness is always achieved on the surface of the application.”
It is normal for a car manufacturer to award LED application contracts to different suppliers – even within one vehicle range.
It is all the more important for the individual suppliers to meet the high quality standard by precise specifications. After all, in the end, a uniform lighting profile must be achieved in and on the vehicle.
The distributor has to ensure optimum series availability and intelligent use of the production batches for both LED manufacturers and suppliers. Even the manufacturers regard the distributor as the main contact point for logistics and advice, so they can concentrate fully on their core skills of product development and production.