When light is planned intelligently, it sparks emotions and creates brand identity so lighting scenes tailored to the target group are therefore becoming increasingly important. Modern lighting solutions make offices and production areas more productive, hotels more cosy, put clothes and accessories in the spotlight, set the stage for works of art or highlight the freshness of foods, whilst ensuring excellent colour rendering. The idea of lighting applications without LEDs is now unthinkable. These compact light sources offer a multitude of benefits, including special light spectra, which can be precisely adapted to the application in question.
Optimised lighting solutions for every purpose
LED specialist Tridonic has spent a great deal of time and effort exploring the possibilities offered by LED technology, which is why it was one of the first companies globally to develop optimised spectra suitable for special applications, such as the illumination of meat, fruit and vegetables in supermarkets. Tridonic’s extensive product range provides solutions for various luminaire types, from spotlights and downlights right through to linear, flat and round luminaires. The modules have been designed for a huge range of applications, covering industrial environments, retail spaces, offices and outdoor areas. Tridonic is constantly sounding out new options with LED technology and boasts a team of experts that focus specifically on searching the market for new components which could be utilised in future LED products.
Strict qualification process for LED components
To guarantee that the quality of the LED modules remains consistently high, Tridonic only uses components in its designs that have successfully passed an extensive qualification programme and which are classified accordingly for the intended use. In addition to the technical evaluation of the components, other quality aspects are also assessed, including patent protection and that raw materials and components are procured exclusively from certified manufacturers.
LED components destined to be fitted on modules are examined in terms of processability – in other words, how easily they can be processed in production by process technology employees, who then assess process capability. They check various aspects, including how well the pick and place process works and whether soldering is possible at the required quality level. These tests ensure that the LED modules are produced reliably and that the company can guarantee its ability to deliver goods.
The reliability of LED modules and components is proven by a range of tests, primarily in line with the international JEDEC standard. The component is classified for different areas of application depending on the result. Golden sample measurements are always carried out for comparative purposes to observe any potential differences in the measurement method between the supplier and Tridonic.
Colour rendering, spectrum and reliability examined meticulously
In the next step of the qualification process, the components are characterised from an optoelectronic perspective. Here, the colour-shift behaviour of the LEDs is checked at different currents and operating temperatures – (-) 40 to (+) 120-degree C. This means that the luminous flux, spectrum, colour rendering and coordinates are measured and compared with the specifications and measurement data from the manufacturer to determine potential deviations in the performance. These measurements are performed cyclically so that possible measurement errors cannot accumulate over time in the photometric measurement equipment.
The next step is all about assessing the components in terms of robustness, colorimetric and photometric aspects as well as mechanical stability – in other words, their reliability. Tests are performed to find out how the components behave in harsh operating conditions. In the ‘high temperature over life time’ test, the light sources are exposed to ambient temperatures of 60 to 90-degree C. Measurements are taken at regular intervals to test the extent to which their properties change. The effect is visible quite quickly as with a bad component, the luminous flux decreases relatively sharply over time, whereas a good component withstands the thousand hours at 90-degree C without a significant reduction in the luminous flux. The additional ‘high temperature, high humidity’ test checks the behaviour of the light source at high temperatures and high humidity – in operation or in storage. Modules for use in outdoor applications, for example, are therefore subjected to an ambient temperature of 85-degree C and a humidity level of 85 per cent. If their forward voltage increases significantly in the process, this indicates an increase of defects in the semiconductor or weak points in the electrical connection technology, which reduces the efficiency and life of the modules.
A temperature shock test reveals mechanical weak points in the connections of the individual component parts. For this, light sources are stored alternately in two different temperature chambers at (-) 40-degree C and (+) 85-degree C over 1,000 cycles. The operating cycle test is particularly important for components which are used in different applications and switched on and off daily. During the test, they must withstand the switch-on process and the associated thermo-mechanical stress in 30-second intervals over several thousand cycles. Tridonic takes this one step further and, with a total of 100,000 cycles, goes far beyond the requirements of the standard for general lighting.
On top of this, the components of the chip-on-board (COB) modules are also subjected to comprehensive final tests because with chip-on-board technology, the individual LED components are only assembled on the printed circuit board, which means that all of the reliability tests need to be carried out once again on the product. With SMD technology, on the other hand, qualification processes are generally not carried out on a product basis any more as the components have already been tested accordingly in the initial qualification process.
Ultimate quality standards – starting from production
Only when the components have successfully passed this three-stage qualification process can the Tridonic experts use them in the design-in of real light sources, which is done in the product development phase. Strict quality standards apply here: Tridonic manufactures products exclusively in line with the highest European specifications with highly automated SMD and COB systems and a high degree of flexibility. Modules are available in four product categories for a multitude of light applications:
- Premium: Modules for special requirements and tasks, such as tuneable white (variable colour temperature control from a warm-white to cool-white LED), for light that can be adjusted on an individual basis.
- Excite: Modules for sophisticated lighting tasks with emotive lighting effects, maximum flexibility and special colours.
- Advanced: Highly efficient modules with excellent light quality.
- Essence: Modules with core functions for application-based specifications.
However, the quality process does not stop with production and before the LED modules leave the production site, they are subjected to a series of intensive final tests. Every product is checked in the factory to see whether it complies with the specifications relating to luminous flux, colour rendering, electrical parameters and – last but not least – efficiency.
Tridonic has patented more than 2,700 innovations to date and its experts have not stopped carrying out research into possibilities of LED technology. Some module series are already in the seventh generation and have been continually improved with each new release. In the past, every new module series generation has boasted an efficiency increase of at least ten percent. In the future, some more efficiency improvements are expected but these will be fairly moderate due to physical limitations. However, heat sinks, reflectors, lenses and mechanical fastening elements still provide great potential for innovation. Generally speaking, the trend towards miniaturisation and the integration of additional functionalities, such as a power supply, communication modules and sensors, can be observed. The company is therefore continuing its research, while maintaining close partnerships with manufacturers as well as national and international standards bodies and academic research institutes, allowing Tridonic to keep playing a pivotal role in the future of light technology.