Jingtai Optoelectronics Technical Director Shao Pengrui: Light Sources with Cost-Performance Advantages Have a Future

CREE's financial report fell short of market expectations, partly due to revenue declines in outdoor lighting such as courtyard lights and street lamps, products that use CREE's self-produced high-power chips. Shao Pengrui, Technical Director of domestic high-power chip manufacturer Jingtai Optoelectronics, believes that what truly drives the development of the LED lighting market is cost, and only light sources with cost-performance advantages have a future.

"LED packaging companies truly need to maintain a mindset of being prepared for danger in times of peace. You must have a certain mentality—you need to do a little more. Go up a little further, go down a little further, let chip manufacturers do their work with peace of mind, we will handle all the solutions, and let application manufacturers use them simply, without too many worries. Only then can packaging companies have better days and truly survive." Jingtai General Manager Gong Wen believes that LED packaging companies should focus.

Jingtai currently focuses on two businesses, implementing a dual-line brand strategy. Within the company's business, the display business accounts for 60% and the lighting business accounts for 40%. According to the latest company performance disclosed by Gong Wenrui, Jingtai's revenue exceeded 400 million in 2013, with over 300 million already achieved in the first half of 2014, and the full-year target is 600 to 700 million.

Shao Pengrui, Technical Director of Jingtai Optoelectronics, is optimistic about the future development of LED lighting. He said that the decline in the average selling price of LED lighting in 2014 will significantly stimulate rapid growth in demand. Price and reliability are currently the most important factors affecting the adoption of LED in indoor lighting.

Cost decline drives LED lighting industry development

Industry analysts noted that CREE's financial results fell short of market expectations, partly due to a decline in revenue from outdoor lighting products such as canopy lights and streetlights, which use CREE's self-produced high-power chips. Shao Pengrui clearly pointed out that it is cost that truly drives the development of the LED lighting market. Light sources with cost-performance advantages are the future. He said: "Ceramic packaging accounts for a large portion of the total material cost. When the cost of LED brackets accounts for a relatively low proportion of the overall LED lighting cost and performance remains unchanged, this type of light source has an advantage."

Shao Pengrui believes that indoor lighting is currently relatively mature, while outdoor lighting in the domestic high-power packaging segment is a blue ocean market this year and next.

LED packaging products have four aspects: mechanical, thermal, optical, and electrical. The main approach is to start with packaging structure and process optimization, and then reflect performance. LED packaging reflects the latter three: First, light control - how to achieve efficient light output? How to meet the lighting needs of different occasions? Second, heat dissipation and thermal conduction channels. With the same heat sink, light sources from different manufacturers have different lumen depreciation rates. Each manufacturer's material structure, design, and process optimization can better reflect the thermal conduction channel. Third, power supply management, including AC-DC conversion and power control - whether the light engine is driven by high voltage, DC, or AC, how to achieve light control and intelligent dimming?

Among the new lighting products launched by Jingtai, there is an IDCOB product, like a light engine product, but objectively speaking, it cannot be purely considered a packaging product; it is a combination of packaging and driver. The advantage of this product lies in the fact that terminal application manufacturers can directly install it in bulbs without needing any power supply, thereby reducing the workload of downstream application manufacturers.

"The ID COB technology solution combines IC packaging and LED packaging, integrating the substrate, power supply, and light source into a unified whole, packaging the driver circuit and LED light-emitting circuit entirely in chip-level form on the substrate. This is a major innovation," Shao Pengrui introduced. "This solution directly uses mains 220V for driving, with overall luminous efficacy above 100LM/W."

"Since this solution eliminates the processes of power supply assembly and SMT placement, application manufacturers only need the cost of one ID COB to cover the cost of substrate, power supply, and light source. The cost-effectiveness is more prominent, with strong market competitiveness." Shao Pengrui believes that this solution will be more convenient in replacing traditional LED bulb lamps. "In the future general lighting market, high-voltage LED will occupy an important position. The ID COB technology process is very simple, suitable for fully automated production. If mass-produced, the market should be larger than that of filament lamps." Shao Pengrui revealed that several manufacturers have already visited Jingtai to discuss related business this year.

Two Major Approaches to Solve Flicker Problems

Professor Mao Yuhai, an expert in LED constant current driver power supply technology, demonstrated the light engine of Eflei Optoelectronics Technology at a seminar organized by Big-Bit. The so-called light engine is the integration of an LED light source and a constant current driver power supply on an aluminum substrate. As long as there is a matching heat sink and housing, it can immediately become a complete LED lighting fixture. Users no longer need to additionally produce driver power supplies, which can greatly reduce the production cost of the entire lamp.

Shao Pengrui, Technical Director of Jingtai Optoelectronics, believes that a major challenge of driverless design is the flicker issue. He points out that Professor Mao Yuhai solved the flicker driver problem with an ingenious method. He added a capacitor to the driver design to solve the flicker problem.

There is another solution: technicians can consider addressing it through the decay time of the phosphor. A conventional capacitor combined with phosphor can also solve it. His observation is that some peers have already reduced the light emission time of LED phosphor to address this issue. For example, why doesn't a 50 Hz incandescent lamp flicker? Because its decay time is relatively long.