LED chip is often referred to as LED lamp beads "heart", its quality is good or bad directly around the LED lights and LED display quality. Small distance LED nowadays hot, for the domestic LED chip manufacturing enterprises to bring opportunities at the same time, also brought challenges. In the LED chip special, I invited Hangzhou Silan Ming core Technology Co., Ltd., Hua Can Photoelectric Co., Ltd., San An Optoelectronics Co., Ltd., Yuan Baobao photoelectric (Shenzhen) Co., Ltd., Xiamen dry photoelectric Co., Ltd. and other enterprises Related to the discussion, a glimpse of LED chip manufacturers in the new situation under the "core design core manufacturing" of the road.
1. In the field of LED display, small pitch is becoming the mainstream of the development of the industry, and this trend is more obvious. Do you think the small gap between the rapid development of the domestic chip manufacturing enterprises will bring what opportunities and challenges?
Shi Lan Ming, general manager of Jiang Zhongyong:
This year's small gap is indeed growing, but we all agree that the growth rate is a bit slow. With the use of small spacing in the display area, its number will increase, and this fact will inevitably put forward higher requirements for product quality. Relative to the enterprise, how to crack technical problems, improve product performance and quality is the survival of enterprises, development, the key to growth. Many companies to seize the current small gap between the development of a great opportunity to meet the difficulties of small-distance products in the difficult points to solve the problem, to produce the market recognized high-quality products, companies will get better survival and development Opportunities, and vice versa may make the enterprise into a passive situation. The current market, the quality of packaging and chip quality has not yet reached a very good state. Therefore, continue to improve the packaging and chip both the quality and stability, as a small pitch enterprises in terms of a long way to go.
Huacan photoelectric marketing director Shi Songgang:
Small pitch LED display technology will be with its no patchwork, excellent display, the next few years will show explosive growth. Small spacing display because of its more dense and the demand for the chip will increase, and the current market capacity continues to increase, we can see in the future there will be no small room for growth, which is a good opportunity for chip companies. But the small spacing of the chip on the chip have a higher technical requirements, such as: how to achieve LED display small current and small capacitance consistency? How can I better meet the high quality of low light and high ash? This requires chip companies continue to enhance the epitaxial and chip technology to meet the needs of the market, and only skilled enterprises in order to stand out in the market competition.
Three security photoelectric product planning manager Guo Yuntao:
The development of small spacing screen, which means that the chip package size will be smaller, the arrangement will be more dense. The requirements for the size of the chip, miniaturization requirements and other optical characteristics will become more stringent requirements.
Jing Yuan Bao Chen, deputy general manager Wang Junbo:
For now, the domestic LED display field has been in the rapid consolidation of which, especially the small pitch of the chip application market, its integration faster than other applications market faster. On the chip business point of view, including the crystal may be three to four main only, I think this pattern should not have much change, because the market through the continuous development of the whole has become mature, Big, and then want to enter this area is not so easy. Small gap between the use of the number of micro-chip chip will be more crystal power for the application of small-scale display of the development of optimistic.
Dry photoelectric chief engineer Zhang Yong:
One of the features of the small pitch display is the high density. High density will increase the use of LED chips, which means that the increase in market demand, no doubt to LED chip manufacturing enterprises to bring new opportunities. Of course, with the chip to reduce the distance between the chip also put forward a higher demand: how to make LED chips with better consistency, reliability, but also to meet the low light, high refresh rate, high scan And other application requirements, which gave LED chip manufacturing enterprises to bring new technical challenges.
2. Small range of products highly integrated, the unit area contains more and more lamp beads, your company is how to improve the chip design, improve the efficiency of the photoelectric conversion chip?
For small-pitch display products, it is precisely because of the lamp beads contained more and more, so it is a single lamp beads brightness requirements are getting lower and lower, the chip photoelectric conversion efficiency is no longer the focus of attention.
This year, Hua Can in the industry took the lead in the introduction of a small pitch dedicated X series chips. The series of chip design direction: the new optimization of the epitaxial and chip technology, to achieve a wide viewing angle, high refresh, low light gray and other quality pursuit of better display, wide viewing angle light consistency, small current photoelectric consistency, Small capacitance to open the consistency and the industry's highest reliability standards to establish X series chips in the industry's quality benchmark, reduce the dead rate, to ensure the stability of the screen body.
For the display, the chip on the main requirements is to improve the whole screen in the high brush when the chip may cause harm, so it will focus on the chip's reliability characteristics.
We have been the misunderstanding of LED products must be the more bright and better. In fact, the focus of small-spaced products is not necessarily in the brightness of how. Because in many cases, the need for low darkness to render the effect. To the chip side, the problem is not out of the photoelectric conversion efficiency, but the screen and other applications are not the same, he is not a constant current operation, how to switch the current when the chip brightness and wavelength can be stable, Small current how to make the chip to maintain performance, this is our homework.
Mainly through the epitaxial structure and chip optimization of the two aspects to improve the chip photoelectric conversion efficiency. For example, in the chip manufacturing, improve the cutting process, increase the chip's luminous area, to improve the lateral luminescence uniformity and light efficiency. In addition, through the optimization of epitaxial structure and material growth conditions, improve the internal quantum efficiency of LED chip, while the choice of materials and thickness of each layer optimization, to meet the optical match, so that LED has a higher light efficiency.
3. Compared with the blue and green chip, red chip technology development and innovation is slow, photoelectric conversion efficiency has yet to be improved. Red chip and blue and green chip to match, often to adjust the current, in the small pitch field, not only lead to greater power consumption, and the product temperature is higher. How does your company promote the technological innovation of the red chip and change this unfavorable situation?
Shi Lan Ming, general manager of Jiang Zhongyong:
With red light to enhance the brightness of this problem, from a technical point of view, has now been completely broken and resolved. But there are two red light in the red: one is positive polarity, one is the reverse polarity. Then the reverse polarity of the red light than the positive red light twice, but the cost will be relatively high. And blue-chip in the cost will be cheaper, while the brightness can also be. In the small distance inside: we choose the chip to be small, the cost is low, there are many companies are stressed the cost, but did not emphasize the quality and reliability of the product. So, usually we do not have to choose the bright red, and most of the positive polarity of the red chip, and now to change this unfavorable situation there are still some difficulties.
In the past two years, the progress of the red AS chip is very slow, which is different from the brightness of the GaN epitaxial wafer. The internal quantum efficiency of the four-element red light extension is very high and lacks the space for improvement. The use of wafer bonding and substrate transfer technology to produce the reverse polarity chip (N electrode up) Although the high brightness, but the cost is high and miniaturization of the chip size is also facing a certain VF higher problem, not Suitable for small pitch display applications. Our countermeasure is to improve the DBR reflection efficiency of the quaternary red epitaxial wafers and the use of surface roughening technology to improve the external quantum efficiency. Our small pitch display red chip is 15% higher in brightness than other manufacturers. Effectively reduce the use of current to reduce heat.
The current part of the red light, throwing in its process continue to enhance the brightness and design, and in the design and development or with the blue-green chip with the common to carry out.
Epistar photoelectric red light product conversion efficiency is almost the same with the blue, in the RGB display, red and blue and green when the three chips used together, the red light in the hot state when the original light will be more than blue light, so Only to increase the current independent. Three kinds of chips to reach the hot state when the brightness will be uniform, so the red light to increase the current This is not a chip efficiency problem, is the material characteristics caused by the difference. Episode Creativity and Innovation In order for customers to always run at the front, the AX series and PN series of two technology platforms with a complete product line, not only to provide chips, but also provide solutions and technical support for customers to create greater additional value.
As we all know, the wafer published WPE 75% of the infrared products reached the world's first, there is another first is the wafer of red light production capacity (the world's first), the product performance is excellent in the world level, and in addition to RGB Screen outside the wider introduction of the application of the rear lights, the reliability of the chip and reliability requirements of all the LED should be the application of the highest and most stringent, so the more valuable crystal red chip quality and reputation The In addition, the wafer has a complete patent layout, since 1996, has been dedicated to innovation in the red product innovation, the constant pursuit of excellence, to be able to do the industry first, production capacity is the world's largest degree, absolutely depends on the use of customers and sure.
Mainly through the red LED chip structure optimization design, improve and improve its manufacturing process to enhance the red photoelectric photoelectric conversion efficiency. For example, absorb some blue and green LED chip technology, improve the red LED chip current expansion layer, increase the current blocking layer, increase the electrode reflection and other means to improve the LED chip current expansion, LED chip light more uniform , At the same time with a better temperature distribution, improve the heat dissipation characteristics, to further enhance the red light LED chip light efficiency.
4. The current pace of development and innovation of the industry significantly accelerated, small spacing, outdoor surface paste, transparent screen, profiled screen is accelerating swept the entire industry. LED display as an important part of the whole industry chain, do you think the chip manufacturing enterprises should keep up with the rapid development of the industry needs? What should I do? What is the future trend of LED chip development?
Shi Lan Ming, general manager of Jiang Zhongyong:
Chip inside the difference is more difficult to do. Because the flow of people inside the chip more frequent, so in the technology or program to do a great difference there is a certain degree of difficulty. For the Silan Ming core, we mainly in the quality management on the continuous refinement, thereby enhancing the quality of the chip, so that the chip produced in the stability of the advantages, to ensure that the flow of products into the market the least, rather than blindly The pursuit of differences in varieties or other differences.
First of all, the chip companies, chip products need to meet the needs of existing market segments, but also to meet future needs of emerging markets to do technical reserves, at any time to respond to market changes, to provide non-homogeneous products. Products to adapt to the market, to be able to take the long term.
Second, companies have to practice hard work, with the packaging customers and application customers. From the application, from the equipment, materials, structure, process methods for system innovation, build industry chain collaborative cooperation, collaborative marketing and collaborative promotion of the situation, the integration of upstream and downstream resources for end users to provide system solutions.
Whether it is outdoor or indoor, the future must be to a small space between the development of the screen. For outdoor chips, in addition to the trend of small spacing, there are trends in the direction of energy development.
The technical level of the problem is the direction of each business main attack: including the problem to overcome the green, the color alone with the problem. When you do a small pitch, you will find the patch this thing is very, very expensive. At present, including crystal power, there are also some enterprises in the technical attempt to use other methods of production, to find a new breakthrough. But from the current form of view, in the short term 1-2 years should not appear in the industrial production pattern.
As LED chip manufacturing enterprises, should be close to the market, close to customers, to the packaging of new technologies and new requirements to respond in a timely manner. To predict the future trend, ahead of some forward-looking research and development work. For example, customers use a new cable equipment or new wire, improved the line process, LED chip can make the electrode to do further. Chip companies also need to adjust the electrode process to meet customer requirements in a timely manner to enhance the performance of LED chips while also reducing the cost. The future With the LED chip chip chip to further reduce the need to minimize the need to take up space occupied by the use of flip chip should be the future direction of the development of LED chips.