Introduction
The LED industry has experienced a major reshuffle, and all ends of the industry chain have entered the era of meager profits. As the core components of LED power supply, electrolytic capacitors are also difficult to resist the pressure of low prices. Some people predict that there is still a possibility of a 10% price reduction this year. And with the large heat of the photoelectric engine without electrolytic capacitor scheme, the LED electrolytic capacitor is facing severe challenges. So, where is the future development direction of LED electrolytic capacitors?
　　01  
volume and life
Two mountains of electrolytic capacitors
The life of LED depends on the power supply, while the life of power supply is subject to capacitors. As the industry calls for the volume and life of capacitors are getting higher and higher, can local capacitor enterprises successfully climb over these two mountains, pass through the quagmire of price war, and make a show in high-end applications?
Huge volume and LED small volume trend
run in the opposite direction
Electrolytic capacitor is one of the most important devices in the primary and secondary circuit filter circuit of switching power supply. The equivalent circuit of electrolytic capacitor is considered to be the series connection of ideal capacitor, parasitic inductance and equivalent series resistance. Since most electrolytic capacitors adopt a winding structure, it is easy to expand the volume, so the capacitance per unit volume is very large, several times to several tens of times larger than other capacitors.
The engineer of Shanghai Ochez Industrial Co., Ltd. believes that the acquisition of large power capacity is at the expense of the expansion of volume. Modern switching power supplies require higher and higher efficiency and smaller volume. The volume of capacitors has become a more serious problem. The dangerous inspection level mentioned that the converter mostly uses boost circuits, so high-voltage resistant aluminum electrolytic capacitors are required. As described above, the aluminum electrolytic capacitor manufactured by the conventional technology needs to absorb a larger pulsating current than the conventional one, and therefore, a capacitor having a larger size has to be selected. As a result, the volume of the power supply is large, and it is difficult to be used in miniaturized electronic devices, especially LEDs, are increasingly developing in the direction of small volume.
Li Shaoke, marketing director of Shenzhen Lyford Optoelectronics Co., Ltd., said in an interview that from the components used in Lyford power supply, electrolytic capacitors account for a large volume of power supply, which leads to a larger volume of LED drive power supply.
Peng Xihe, deputy general manager of research and development of Mingwei (Guangzhou) Electronics Co., Ltd., also mentioned that LED drivers are developing towards reducing the volume and cost in design, and at the same time, they have to cope with the harsh use environment. The demand for designers is more demanding, hoping to increase the capacitance ratio to meet the demand for small volume.
When Aladdin News Center interviewed some power supply companies in the industry, it was found that one of the most frequently mentioned problems is that the existence of capacitors leads to the problem of increasing the volume of LED drive power supply. Capacitors, transformers and inductors, the "three big pieces" that affect the volume of LED drive power supply, and capacitors bear the brunt. LED power supplies and LED lamps are developing in the direction of small volume, and the existence of capacitors just hinders or slows down the pace of this development trend. However, from some alternative schemes on the market at present, such as "de-powering", although the "three big pieces" have been eliminated and there has been a great leap in volume, there are inevitable shortcomings in the performance of the product, which can not be widely recognized. Volume and performance, it seems that the LED drive power can not have both things, which is also a big problem in front of the capacitor enterprises.
Low temperature adaptability leads to short life
into a capacitor short board
There is a popular saying in the LED industry that 80% of the failure problems of LED lamps are caused by the LED drive power supply. Perhaps we are all wrong about the LED drive power supply. The real problem is actually a component in the LED power supply-capacitor.
Zhang Weili, manager of Yingfei Electronics Market Planning Center, mentioned that the reliability and stability of electrolytic capacitors are still low under high temperature conditions, especially the abnormal failure of high-voltage electrolytic capacitors at a stage far below the expected life is still very common, and this problem is particularly prominent in LED lamps with poor working environment.
Chen Hao, director of Maoshuo electronic products, said that the adaptability of capacitors to working temperature needs to be wider. For example, in extremely cold areas, the electrolyte will change its capacity due to freezing, which will eventually affect the normal operation of the driving power supply, while too high temperature will affect the service life.
Peng Xihe mentioned that LED drivers are mostly driven by devices in lamps and lanterns. Its own temperature rise and the temperature rise of lamps and lanterns can easily exceed the upper temperature limit for electrolytic capacitors. Although this depends on the cognition of lamp system design engineers, practical applications often exceed the upper temperature limit of capacitors and require electrolytic capacitors to have good temperature resistance.
Commonly used electrolytic capacitors are electrolytic capacitors using liquid electrolyte. Once the electrolyte is dry, the capacitance is naturally gone. The higher the temperature, the easier it is for the electrolyte to evaporate. At present, all electrolytic capacitors are marked at 105 degrees C life. Simply put, if the ambient temperature is higher than 105 ℃, then its life will be less than 1,000 hours, if the ambient temperature is lower than 105 ℃, then its life will be higher than 1,000 hours, the ambient temperature and the life of the capacitor has the simplest and most easily calculated relationship, that is, the ambient temperature increases by 10 degrees, the life will be reduced by half, life is doubled.
In some extremely cold areas, the electrolyte activity is reduced or even directly unable to work, and the temperature is too high will greatly shorten the life of the electrolytic capacitor. Due to the influence of factors such as LED internal space compression, heat dissipation design, sealing process and price competition, the life and reliability of capacitors have become the biggest voice of power supply enterprises.
Domestic capacitor innovation ability is low,
Product quality cannot meet the application
Zhang Weili believes that electrolytic capacitors, as low-cost and high-energy-density energy storage components, play an important role in power supply design. Although there are not too many technical obstacles to completely eliminate electrolytic capacitors in power supply design, it will always cause a series of problems such as the reduction of lightning protection capability and the deterioration of some electrical technical indicators. Although these problems have technical means to solve, they will often significantly increase the cost of power supply, the price/performance ratio is difficult to be widely recognized.
Therefore, the future for a considerable period of time in the electrolytic capacitor in the high power of the mainstream LED power products will still exist, in some of the price is not sensitive, the life and reliability of more concerned about the high-end occasions, electrolytic capacitor design may be welcomed.
At the same time, the quality of domestic capacitor products can not meet the application needs of the high-end market, and can only appear as a kind of spare goods, which is quite embarrassing. Local capacitor enterprises, on the one hand, started late, lack of details without the baptism of time, and their innovation ability is slightly insufficient; on the other hand, the rapid development of China's economy has led enterprises to start price competition prematurely, and most enterprises have the phenomenon of "making quick money", which further aggravates the problem of product quality.
Capacitor enterprises in the face of the size and life of these two mountains, but also to consider the impact of the price war, perhaps, the next is the real test of the local capacitor enterprise innovation ability of the time.
　　02 
electrolytic capacitor to fine:
Low voltage patch scheme provides reference for the industry
The discussion between LED electrolytic capacitor and power supply life continues. Previously, the view that "the short life of LED lamps is mainly due to the short life of power supply, and the short life of power supply is due to the short life of electrolytic capacitor" is one-sided, but it also makes the market put forward many requirements for the quality of electrolytic capacitor. The problems of insufficient quality and excess quality of electrolytic capacitor all prompt electrolytic capacitor enterprises to put forward more efficient solutions.
As the key component of LED power supply, the life of electrolytic capacitor determines the life of LED lamp, but on the other hand, considering the limitation of circuit board area and power supply design, the capacitor needs to reduce the volume and maintain good high temperature resistance. How to balance the relationship between the two? Integrated current capacitor miniaturization, long life, high reliability needs, in the pursuit of the best cost-effective premise, the technical solutions of various electrolytic capacitor companies and what are the highlights, can provide more ideas for the development of the industry?
Each enterprise has different requirements for the product characteristics of LED capacitors. At present, cost performance is the dominant factor, but the market will eventually move towards the development of high-end manufacturing. For this reason, Yunxing has also introduced patch aluminum electrolytic capacitors to solve some high-end customers' requirements for machine patch production, namely machine automation.
Comprehensive various technical solutions to extend the life of LED electrolytic capacitors can be put forward from both internal and external factors.
At present, the commonly used electrolytic capacitors mainly use liquid electrolyte, and the electrolyte is closely related to the working environment temperature. Generally speaking, it can be roughly considered that the service life will be reduced by half when the ambient temperature increases by 10 degrees. In turn, the service life will be doubled when the ambient temperature decreases. Therefore, high temperature resistance has become an urgent technical point for electrolytic capacitors to break through. In view of this Yunxing electronic guide pin type LED electrolytic capacitor scheme, it has introduced two new products of high temperature resistant patch: the coated aluminum shell patch can be reflowed at 260 ℃ without bottom bulging, and the other internal explosion-proof aluminum shell plus sleeve patch can be reflowed at 240 ℃ without bottom bulging, with the main cost performance.
Cloud Star Electronics also proposes different targeted solutions for low-voltage and medium-high-voltage patch electrolysis schemes. As a relatively mature low-voltage patch electrolysis market, the electrolyte of general manufacturers adopts γ-butyl lipid system, which can ensure that it does not contain water and has good wide temperature performance. However, at the same time, the shortcomings are also prominent, the quality control requirements are strict, and the consistency and stability are difficult to grasp. At the same time, we know that electrolytic capacitors should also pay more attention to reducing the influence of ripple current on them in use, poor product impedance poses a serious challenge to the quality of electrolytic capacitors.
Yunxing Electronics takes a different approach and adopts other mixed solvents, which not only ensures the wide temperature characteristics of the product (reflow soldering at 260 ℃), but also does not have strict control over moisture and the like in the manufacturing process, which can ensure good life characteristics of each batch of products, and the impedance at high frequency is much lower than that of patch electrolysis of γ-butyl lipid system.
For the medium and high voltage patch electrolysis market, due to the structural reasons of the end market board and some technical difficulties, the demand and application of long-life patches for mass production and sales are too high, but with the update of the end market structure, the related demand is believed to grow rapidly. In view of this, Yunxing Electronics through the adjustment of materials and structure, so that the life of medium and high voltage patch electrolysis can be as long as 12000H, as the industry, reference is of great significance.
The next stage of growth of electrolytic capacitors may be in the LED alternative market, which also provides a reference for the next product plan of electrolytic capacitor enterprises. To address the miniaturization of LED lights and the growing demand for automated production, companies will need to focus on providing customized solutions and services.
　　03  
In the era of small profits,
The way to break the situation of LED electrolytic capacitor
The LED industry has experienced a major reshuffle, and all ends of the industry chain have entered the era of meager profits. As the core components of LED power supply, electrolytic capacitors are also difficult to resist the pressure of low prices. "The overall price of LEDs has fallen too fast, and we can only reduce the adverse impact of price declines on the company's operating performance through volume growth." Chen Zhenghua, general manager of Fujian Yunxing Electronics Co., Ltd., a domestic LED electrolytic capacitor brand enterprise, said in an interview. Although the price of LED electrolytic capacitor products is close to the bottom line, there is still the possibility of 10% price reduction this year.
In addition, linear IC with the photoelectric engine of the heat, the market gradually up, one of the no electrolytic capacitor scheme directly to the traditional capacitor, for electrolytic capacitor enterprises to pose a great challenge. The future of electrolytic capacitors or will gradually fade out of the market?
Electrolytic capacitors are still essential
Aladdin News Center has an in-depth understanding that most power supply companies believe that electrolytic capacitors are still one of the indispensable key components in the future, especially in sports venues, street lights and high-demand stroboscopic lighting applications. "The low-frequency flicker caused by the high ripple current of the electrolytic capacitor will cause discomfort to the human eye or physiology." Tan Chao, R & D manager of Guangdong Kogu Power Supply Co., Ltd., said.
Guo Junxiong, business development manager of LED Power Division of Quanhan Enterprise Co., Ltd., believes that the advantages of electrolytic capacitors lie in high capacity and low cost. Although the use conditions are limited, they can still meet the use of most indoor business environments. "In the absence of other new materials to replace the situation, there is still a need to exist."
As a low cost, high energy density energy storage element, electrolytic capacitor plays an important role in power supply design. Although the electrolytic capacitor is completely eliminated in the power supply design, there are not too many technical obstacles, but it will cause a series of problems such as the reduction of lightning protection ability and the deterioration of electrical technical indicators. These problems can be solved by technical means, but it will also significantly increase the cost of the power supply and reduce the cost performance accordingly.
Zhang Weili, manager of Infeite Electronics Market Planning Center, concluded, "Electrolytic capacitors will still exist in medium and high-power mainstream LED power products for a long time in the future. In some high-end occasions that are not sensitive to price and pay more attention to life and reliability, the design of electrolytic capacitors may be welcomed. Of course, it is another matter to be willing to sacrifice some technical performance such as power factor or LED ripple current in exchange for low-end applications without electrolytic capacitor design."
Chen Hao, director of Maoshuo electronic products, believes that electrolytic capacitors will still play an irreplaceable role in specific applications such as energy storage, filtering, coupling and output smoothing in the future. For example, in the fields of power adapter, automobile charging pile, inverter, etc., electrolytic capacitor is one of the essential main energy storage devices.
While affirming the value of electrolytic capacitors, power companies also put forward higher technical and performance requirements, such as small size, large capacity, low ripple current, long life, and increased operating temperature.
"Electrolytic capacitors need to improve their tolerance to ripple current without reducing reliability and life, which helps reduce the size and cost of switching power supplies. In addition, the filtering effect of electrolytic capacitors on high-frequency ripple and overvoltage resistance also need to be improved." Zhang Weili said that the power supply enterprises to enhance the requirements of electrolytic capacitors.
Peng Xihe, vice president of research and development of Mingwei (Guangzhou) Electronics Co., Ltd., believes that electrolytic capacitors are primarily stable and controlled in quality, followed by breakthroughs in characteristics. "This requires electrolytic manufacturers to strictly control the quality of products, but there are not many manufacturers who can make capacitors seriously at present."
The way to break the situation of electrolytic capacitors
The heavy pressure of the meager profit era, the many criticisms that still exist in capacitors, the impact of new technologies, and the continuous optimization needs of downstream customers... In the new industrial environment, how should LED electrolytic capacitor companies develop?
In view of the short life of traditional liquid aluminum electrolytic capacitors, electrolytic capacitor companies have introduced solid electrolysis, which has the characteristics of high stability and long life, and can optimize most of the application requirements in the design of new high-end power supply lines. However, due to the high price, the current market of this product is mainly located in the consumer power communication power market, and it is more used in the outdoor field with harsh conditions in the LED field.
"This product will be the future development direction of aluminum electrolytic capacitors, and the market prospect is broad. However, from the current technology, solid capacitors still have a long way to go to replace liquid aluminum electrolytic capacitors." Chen Zhenghua analysis, first, because the application range of solid electrolytic voltage is still limited to medium and low voltage, high voltage still has a long way to go in the technical level; second, liquid aluminum electrolytic capacitor technology is mature, which can meet the requirements of most markets, and the cost advantage is obvious, especially for the general lighting market, the cost advantage of aluminum electrolytic capacitor is unshakable.
In order to seize the incremental market share of high-end market, the future research and development focus of electrolytic capacitor enterprises is to reduce the fixed electrolysis cost and improve the voltage application range.
As we all know, transformers and electrolytic capacitors occupy most of the volume of power components, and considering the limitation of the circuit board area, the miniaturization of capacitors is considered to be the inevitable trend of future development.
Chen Zhenghua said that with the continuous progress of society and the rapid requirements of applications, the future development of micro-packaged devices has a trend to replace ordinary packaged devices. Small volume electrolytic capacitors, especially SMD aluminum electrolytic capacitors, as a new type of passive components with light weight, thin thickness and small size, are suitable for various electronic products with compact structure, small size and high precision, and have a very wide application field.
At the same time, the era of industrial 4.0 puts forward higher requirements for automated production, and small-volume patch aluminum electrolytic capacitors are in line with this application trend and are recognized by the major high-end markets. "Small size, long life, low price competition will be the future development direction of LED electrolytic capacitor enterprises."
It is understood that in the LED business, Yunxing's share in the small-volume market has reached more than 90%. However, with the increasingly "demanding" volume requirements for electrolysis, enterprises need to cooperate and integrate with the supply chain to better apply ultra-miniaturized electrolysis to LED products. At this stage, if we do not improve the technical materials and core equipment, it is difficult to achieve the requirements of ultra-miniaturization.
Summary
In the past two years, the profits of aluminum electrolytic capacitors are still gathered in the alternative market of LED, but this part of the market does not have the possibility of explosive growth. If we only insist on opening up the red sea market of general lighting, how difficult the road of development is. LED electrolytic capacitor enterprises should combine their own advantages, or realize production automation and conquer the miniaturization market. Or provide customized solutions and services to meet the needs of the diversified era; Or open up new blue ocean fields such as solid electrolysis and integration into intelligence, seek high gross profit market and realize magnificent transformation.