LED lighting offers substantial energy savings and enhanced product life, but the challenge is to manufacture products comparable in cost, colour and brightness to replace incandescent or fluorescent bulbs, in order to encourage widespread adoption
The demand for LEDs has witnessed significant growth in recent years, driven by lighting for signage, automotive, industrial sites and backlit televisions. Domestic lighting is expected to become the most significant growth driver in this sector over the next few years, as various government policies are encouraging consumers to switch from incandescent bulbs to more energy-efficient LEDs.
Advances in LED manufacturing
Various ongoing developments in LED manufacturing facilitate energy efficiency and cost reduction. This has resulted in assembly lines gearing up to provide higher output, quicker throughput and faster mould-change timings. Machines today implement new manufacturing processes like cold injection-moulding, specially customised by OEMs.
Many new processes are designed specifically for street lighting applications and are perfect for wide area lighting, both outdoor and indoor. New optical techniques provide the flexibility to sharpen extreme angles and elaborate specific design geometries have been developed in order to make innovative lenses that can achieve a superior optical refractive index, while delivering an optical performance level that perfectly complies with the optical efficiency requirements of the current generation of LEDs.
The transition to LED usage in general lighting applications has also impacted the tool and mould makers. In general lighting LEDs, the continual advances require a constant influx of capital and prudent investments. This has a direct impact on the cost of ownership but considering the international levels of technology, it has become an accepted norm.
Technology thrust
Many new LED manufacturing techniques like rotary-type LED lamp assembly lines are fast gaining momentum in various markets. The industry has been in the learning mode and thanks to adequate research and development being undertaken by a large number of corporates and academic institutions, knowledge-sharing has now become faster.
A rotary type of LED line is mainly used for automatic LED lamp assembly. This line is high on technology and boasts of characteristics like temperature-adaptability, energy saving, environmental protection, great market potential and high production efficiency. The quality of the final assembled product is consistent and hence this can successfully replace a manual assembly set-up. This line finds wide application in the energy-saving automatic assembly equipment industry.
The market for LEDs is fast expanding and apart from high-end commercial applications, domestic buyers are contributing significantly to the growth of this sector. However, catering to such a vast number of consumers entails considerable research that translates into real-time applications.
Meeting key industry requirements
LED manufacturing machines today must be internationally acceptable in order to be installed in any set-up across the globe. They must be energy-saving, environmentally compatible, have a wide application range, high production efficiency, and stable quality. These machines must ensure intelligent control of the entire production process, a seamless rotary operation, counter-clockwise rotation and water-based operations as well. This ensures simple operation, easy in-line changing and convenient maintenance. Only then can they entirely replace the manual LED bulb assembly process.
Efficient manufacturing also requires early detection of errors and faster methods for rectification. This makes in-line monitoring a critical aspect in the production process as it helps determine how defects affect the yield. Hence, a proper strategy would have a positive impact on the returns on investment for LED manufacturers of all sizes. Advanced defect and yield analysis solutions are needed to enable the process control loop.
As a standard industry norm, most LED manufacturers today rely on inspection tools to inspect and display defects. ‘Defect density’ is typically the parameter for statistical process control (SPC) at different stages of the process. However, the drawback of this approach is that a lot of ‘defects’ that do not cause yield loss can get highlighted, resulting in unnecessarily hampering the manufacturing process.
Many companies still follow the method of using ‘total defect density’ which has been rendered impractical by current technology standards. This has a regressive impact on the final performance in terms of throughput and uniformity. In many countries, LED manufacturing still involves techniques that would be considered obsolete in most semiconductor industries. This, however, can be counter-balanced by the constant emergence of large LED players who will speed up the adoption of the latest manufacturing paradigms based on their global exposure.
Paving the way for efficient manufacturing
Buoyed by the ongoing and constant need to innovate and evolve with time, LED equipment manufacturers around the world are gradually understanding the dynamics of this hot market and the fragmented requirements of industry stakeholders at all levels. For LED manufacturers to stay competitive in this challenging environment, they need to have a comprehensive production process control strategy which will not only improve yield but remain cost effective.
By Anwesh Koley
