[China's Semiconductor Lighting Network] Due to the public habits, well-known traditional incandescent light-emitting form of large-angle and trend of back-to-ancients, let the resembled incandescent filament, LED lamp, found its
exclusive application position. Therefore, the foreign demand of LED filament lamp is increasing. Besides, since the production of LED filament lamp manufacturing technology is similar to incandescent lamps, it would be absolutely easy for those long-lived incandescent lighting manufacturers transfer to produce LED filament lamp. With the LED filament lamp from the theory to the reality of lighting products, from decorative applications to functional lighting, the demand will be growing day by day. At present, the manufacturers of this field are over 600!
In the technical composition, the filament is in a closed environment and the substrate area of the LED filament is too small. Under the requirement of small light failure and long life requirements, would the practical application of heat radiation be perfectly designed? What are the methods to ensure that the technical performance of LED filament lamps meet the application of quality requirements? At 8:00 pm on November 22nd, the LED industry elite group of WeChat proceeding a depth dialogue on the future of LED filament lamp, the following is the dialogue:
【Topic】: Will LED filament lamp become the mainstream of bulb light source?
The technical composition and technical requirements of the LED filament lamp, LED filament lamp accessories constitute:
1. transparent glass
2. Solid crystal (normal) or flip chip (flip) filament;
3. Metal materials (iron, aluminum, etc.) screw plug;
4. Power supply.
The technical requirements of LED filament lamp:
1. No blue light overflow;
2. High color rendering (Ra> 90);
3. No flicker;
4. High luminous efficiency (110 ~ 125Lm / W)
5. Light-emitting angle (> 320 degrees)
6. Replacement (traditional interface, E14, E27, etc.; as for boundary dimensions, A60, C35LED filament lamp are in the majority)
7. Excellent heat dissipation (with small light attenuation and long life requirements)
At the discussion session, it was suggested that since the current LED bulb family has reached the basic application requirements and the price has been accepted by the general public, why should we have to exploit LED filament lamp at the same spherical light? Column Moderator Chen Bingquan Respond: compared the LED filament lamp with LED bulb light at quality performance, let’s say, if the two technology applications are mature equally, its performance is just like the German BMW car and domestic QQ car comparison - the same product, but not in the same level with different quality and performance requirements. The price and application sites are different and ordinary LED bulb cannot meet the needs at some applications that LED can do. It is the charm and beautiful future that LED filament lamp owning. There is no doubt several indicators of LED filament lamp are far-fetched, such as heat radiation and light failure which is based on LED filament lamp limited small substrate area. To develop filament lamp in the long-term, break through the inherent idea of LED lighting is very important. My personal view is that we should improve the filament lamp filament structure, because filling inert gas has o long way to reach the design effect to achieve the purpose of heating radiation. Since the LED filament applied COB chip package, we can use some effective technical means to reduce heat or rapid thermal conductivity of the LED filament lamp which is the assurance of low light failure and long life, such as substrate shape optimization, substrate material selection and thermoelectric split mode and etc.
As for the discussion of non-stroboscopic of LED filament lamp, column host Chen Bingquan posted that in a small volume and small installation space, limited installation space is very stringent with the components volume. For now, only high voltage linearity can fitting with the current low-power and small installation space of drive power products. Due to the "hole" effect caused by the high-voltage linearity in the rapid current passing, it is very difficult to realize the non-flicker in the mass production without compensation in the absence of fine technical means. At this respect, the high voltage linearity manufacturers are no absolute means to completely eradicate strobe. They can only use technical means to reduce the "hole" effect and get the strobe under controlled in a certain range.
The discussion of the application prospects of LED light filament lamp, Xingbao Aurora lighting General Manager Li Zihao consider that there is a significant development of LED filament lamp in the future cost and personalization. Column host Chen Bingquan hold on the contrary opinion that the performance of LED filament lamp can be solidified well, but it fall back to traditional applications, such as general lighting, retro decorative lighting, crystal chandeliers, lanterns, etc.. This is a difficult unified for the LED Filament lamp, or at this stage the decorative meaning is greater than the meaning of lighting functions. As for the current technological development, lighting function can be expected soon. General manager of Kuiruipu, Liu Hui think that the filling of abortion gas to achieve cooling purposes cannot solve the fundamental cooling problem, which can only say heating radiation better, but the light still exists a big decline. In the application, it also exposed the LED filament lamp’s internal problems: the first party refused to use filament lamp at my several projects on the grounds that the price is high, the lamps do not achieve the role of decoration when it is off light l, and finally they selected the patch of bubble.
In the course of the discussion, Yi Zhihui the general manager made a comprehensive description of the LED filament lamp: LED filament lamp cooling and light attenuation problems should not be ignored. Although there are many LED filament lamp manufacturers, those several large traditional light bulb enterprises have mature technology! Technology and cost controlling are very important for LED filament lamp. As for current show, two years earlier many exhibitors in this area are getting less and less. The lights fair almost fade away. The existing chip structure technology certainly did not reach the traditional lamp power, unless the chip through an innovation. Filling inert gas cannot solve the fundamental problem of cooling which can only work a little better, but the light still has a big decline. The previous report pointed out that they are working on reducing the cooling impact of light decline. According to the law of conservation of energy determines the current chip technology, LED filament lamp cannot reach high power and it can only do decorative lighting function. When LED filament lamp enlarged the volume, it also expanded the size of the cooling area which is simply useless to high power. If the light source separated from lamps, we returned to the "tungsten lamp era" again, which is not the desired outcome for LED era. In my opinion, our application must not get into a blind alley, or we would live down to predecessors creating a precedent for us. Since we engaged in the application, we should make full use of it and create cost-effective products for consumers. I remember that when we find OLED, there is discussion about the two semiconductors’ competition? Will the LED eliminated?
China's semiconductor lighting network editor, Chen Guansheng, also hold on the application of LED filament lamp view that its future market can be expected, as long as the filament lamp does not exist technology problem, the product is no problem, and the price can be accepted by average consumers.
Yu yuanqiang, chairman of the Ya Chengwei, viewed that LED filament lamp is more beautiful in light decoration, focusing on low-power bulb and candle bubble-based but not light effect and lifetime.
Zhang Dongyuan, deputy general manager of Wanjiaguang, made a question: below 5W, filament lamp bulb and candle lamp have some advantages and they can replace the 40W incandescent lamp. How did A60 filament lamp replace over 60W incandescent? How much power do you need? How about cooling and life expectancy? Presenter Chen Bingquan answered:
1. 60W incandescent owns the published light efficiency about 15Lm / W and the beam angle about 330 degrees. When it compared to the current LED light filament lamp parameters on the use of HVLEDs technology, luminous efficiency of 100 ~ 130Lm / W, it just hold the line with or over the incandescent light effect. If the parameters of LED filament lamp can be stabilized, it can be achieved about 6WLED filament lamp replacing 60W incandescent lamp. The issues of cooling, filament, drive, etc. also need to be demonstrated. After all, the above several technical items can impact LED filament lamp to achieve the desired performance?
2. As for the cooling problems affecting the decline light of LED filament lamp and life expectancy, it is farfetched to rely on inert gas filling to achieve the desired effect of heating radiation. These two issues still need filament lamp technology efforts. As for the light decline and life expectancy, in my opinion, it depends on those who engaged in improving filament lamp filament structure, the whole lamp structure, optimized package in this technology research and development. Yuan chengjun, general manager of Jisi photoelectricity, gave the answer at this stage that although LED filament lamp has short life expectancy and fast light failure, this thing can also use a year, and one and a half years or so.