Introduction

The LED industry has undergone a major reshuffle, and all ends of the industry chain have entered the era of meager profits one after another. Some people predict that there is still a possibility of a 10% price cut this year. And with the popularity of photoelectric engines without electrolytic capacitors, LED electrolytic capacitors are facing severe challenges. So, where is the future development direction of LED electrolytic capacitors?

size and life

Two mountains of electrolytic capacitors

The life of LED depends on the power supply, and the life of the power supply is limited by the capacitor. As the industry calls for the volume and life of capacitors, can local capacitor companies successfully overcome these two mountains and go through the quagmire of price wars. Application occasions to show their strength?

Huge volume and LED small volume trend

run in the opposite direction

Electrolytic capacitors are one of the most important devices in primary and secondary loop filter circuits in switching power supplies. The equivalent circuit of electrolytic capacitors is considered to be the series connection of ideal capacitors, parasitic inductances and equivalent series resistances. Since most electrolytic capacitors use a winding structure, it is easy to expand the volume, so the capacitance per unit volume is very large, several to dozens of times larger than other capacitors.

Wei Jianping, an engineer of Shanghai Ouqies Industrial Co., Ltd., believes that the acquisition of large capacitance is at the expense of volume expansion. Modern switching power supplies require higher and higher efficiency and smaller volume. The volume of capacitors has become a more serious problem. Dangerous Inspection Ping mentioned that converters mostly use boost circuits, so high-voltage aluminum electrolytic capacitors are required. As a result, since the aluminum electrolytic capacitors manufactured by the conventional technology have to absorb a larger pulsating current than the conventional ones, a large-sized capacitor has to be selected. As a result, the power supply is bulky and difficult to use in miniaturized electronic devices, especially LEDs are increasingly developing towards smaller volumes.

Li Shaoke, Marketing Director of Shenzhen Lifeford Optoelectronics Co., Ltd., said in an interview that from the components used in the Lifeford power supply, electrolytic capacitors account for a large volume of the power supply, which leads to the larger volume of the LED drive power supply.

Peng Xihe, deputy general manager of research and development of MEAN WELL (Guangzhou) Electronics Co., Ltd., also mentioned that LED drivers are developing towards reducing size and cost in design, and at the same time, they have to cope with the harsh use environment. It is hoped to increase the capacitance ratio of the capacitor to meet the needs of small volume.

In an interview with some power supply companies in the industry, Aladdin News Center found that one of the most frequently mentioned problems is that the existence of capacitors causes the LED drive power supply to become larger. Capacitors, transformers and inductors are the "three major components" that affect the volume of LED drive power, 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. From the current market alternative solutions such as "de-power supply", although the "three major items" have been eliminated, the volume has made a great leap, but there are inevitable shortcomings in the performance of the product. , which cannot be widely recognized. Volume and performance seem to have become something that LED drive power cannot have at the same time, which is also a major problem for capacitor companies.

Low temperature adaptability leads to short lifespan

A capacitor short board

There is a popular saying in the LED industry that 80% of the failures of LED lamps are caused by the LED drive power supply. Maybe we all blame the LED drive power supply. The real problem is actually a component in the LED power supply - the capacitor. .

Zhang Weili, manager of the Marketing Planning Center of Inventel Electronics, 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. , This problem is particularly prominent in LED lamps with harsh working conditions.

Chen Hao, director of electronic products of Maoshuo, said that the adaptability of capacitors to working temperature needs to be wider. For example, in extremely cold regions, the electrolyte will change its capacitance due to freezing, which will eventually affect the drive power supply to work normally, and the temperature will be too high. will affect lifespan.

Peng Xihe mentioned that the LED driver is mostly driven by the device in the lamp. The temperature rise of the lamp itself and the temperature rise of the lamp can easily exceed the upper temperature limit for the electrolytic capacitor. Although this depends on the cognition of the lighting system design engineer, but Practical applications often exceed the upper limit of the temperature resistance of the capacitor, and the electrolytic capacitor itself needs to have good temperature resistance.

Commonly used electrolytic capacitors are electrolytic capacitors that use liquid electrolyte. Once the electrolyte is dry, the capacitance will naturally disappear. The higher the temperature, the easier the electrolyte will evaporate. All current electrolytic capacitors are marked with life at 105°C. Simply put, if the ambient temperature is higher than 105°C, then its lifetime will be less than 1,000 hours, and if the ambient temperature is lower than 105°C, then its lifetime will be higher than 1,000 hours, the ambient temperature and capacitor lifetime There is a relationship that is simplest and easy to calculate, that is, for every 10 degrees increase in ambient temperature, the life is reduced by half; conversely, for every 10 degrees decrease in ambient temperature, the life is doubled.

In some extremely cold regions, the activity of the electrolyte decreases or even cannot work directly, and the high temperature will greatly shorten the life of the electrolytic capacitor. Affected by factors such as the shrinking of the LED volume leading to the compression of the internal space of the LED, the quality of the heat dissipation design, the sealing process and the shoddy charging caused by the price competition, the lifespan and reliability of the capacitor have become the most popular part of the power supply enterprise.

The innovation ability of domestic capacitors is low,

The product quality cannot meet the application

Zhang Weili believes that electrolytic capacitors play an important role in power supply design as a low-cost, high-energy-density energy storage element. Although there are not too many technical obstacles to completely cancel electrolytic capacitors in power supply design, it will always cause problems such as There are a series of problems such as the reduction of lightning protection capability and the deterioration of some electrical technical indicators. Although these problems are solved by technical means, they often significantly increase the cost of the power supply, and the cost performance is difficult to be widely recognized.

Therefore, electrolytic capacitors will still exist in mainstream LED power supply products with medium and high power for quite some 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.

At the same time, the quality of domestic capacitor products cannot meet the application needs of the high-end market, and can only appear as a spare, which is quite embarrassing. Local capacitor companies, on the one hand, started late, lacking in the background without the baptism of time, and their innovation ability is slightly insufficient; The phenomenon of "making quick money" further exacerbated the problem of product quality.

While facing the two mountains of volume and life, capacitor companies must also consider the impact of price wars. Perhaps, the next time is to truly test the innovation capabilities of local capacitor companies.

Electrolytic capacitors are becoming more refined

The low-voltage patch solution provides reference ideas for the industry

The discussion between LED electrolytic capacitors and the life of the power supply has continued. The previous view that "the short life of LED lamps is mainly due to the short life of the power supply, and the short life of the power supply is due to the short life of the electrolytic capacitor" is relatively one-sided. However, the market has put forward many requirements for the quality of electrolytic capacitors. The problems of insufficient quality and excess quality of electrolytic capacitors have prompted electrolytic capacitor companies to propose more efficient solutions.

As a key component of LED power supply, electrolytic capacitors determine the lifespan of LED lamps. On the other hand, considering the limitations of circuit board area and power supply design, capacitors need to be reduced in size and maintain good high temperature resistance properties. How to balance The relationship between the two? Considering the current needs of capacitor miniaturization, long life, and high reliability, under the premise of pursuing the best cost-effectiveness, what are the highlights of the technical solutions of various electrolytic capacitor companies, which can provide more ideas for the development of the industry?

Different companies have 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 launched SMD aluminum electrolytic capacitors to solve some high-end manufacturing. The customer's requirements for machine patch production, that is, machine automation.

Combining various technical solutions, extending the life of LED electrolytic capacitors can propose technical solutions 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 every time the ambient temperature increases by 10 degrees, its life span will be reduced by half; conversely, every time the ambient temperature decreases, the life span It will be doubled, so high temperature resistance has become a technical point that electrolytic capacitors need to break through. For this, Yunxing Electronic's lead-pin LED electrolytic capacitor solution is worthy of attention, and it has launched two new high-temperature-resistant SMD products for this: the coated aluminum shell SMD can pass 260 ℃ reflow soldering without bulging, and the other internal Explosion-proof aluminum shell and sleeve patch can pass 240 ℃ reflow soldering without drum bottom, and the main cost-effective.

For low-voltage and medium-high voltage patch electrolysis solutions, Yunxing Electronics also proposes different targeted solutions. As a relatively mature low-voltage patch electrolysis market, general manufacturers use the γ-butyrolactone system for the electrolyte, which can ensure that it does not contain water and has good wide temperature performance, but at the same time, the shortcomings are also more prominent, strict quality control requirements, consistency and Stability is 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. Poor product impedance poses a serious challenge to the quality of electrolytic capacitors.

Yunxing Electronics takes a different approach and uses other mixed solvents, which not only ensures the wide temperature characteristics of the product (can pass 260 ℃ reflow soldering), but also does not have strict control of moisture and other γ-butyrolactone systems during the production process, which can guarantee The life characteristics of each batch of products are good, and the impedance at high frequency is much lower than that of the patch electrolysis of the γ-butyrolactone system.

For the medium and high voltage SMD electrolysis market, the demand and application of mass-produced and sold long-life SMD are not too high due to the structural reasons of the terminal market and some technical difficulties. However, with the update of the terminal market structure, the relevant demand is believed will also grow rapidly. In response to this, Yunxing Electronics has made the life of medium and high voltage patch electrolysis up to 12000H through the adjustment of materials and structures. As an industry, it is of great significance for reference.

The next stage of growth of electrolytic capacitors may be in the LED replacement market, and this also provides ideas for the next product plan of electrolytic capacitor companies. To solve the demand for miniaturization of LED lamps and the growing demand for automated production, companies will need to pay more attention to providing customized solutions and services.

The era of low profit

The Breakthrough of LED Electrolytic Capacitors

The LED industry has undergone a major reshuffle, and all ends of the industry chain have entered the era of meager profits one after another. "The overall price of LEDs is falling too fast. We can only increase the volume to reduce the adverse impact of the price drop on the company's operating performance." Chen Zhenghua, general manager of Fujian Yunxing Electronics Co., Ltd., a domestic LED electrolytic capacitor brand company, said in an interview. . Even though the price of LED electrolytic capacitor products is close to the bottom line, there is still the possibility of a 10% price reduction this year.

In addition, with the popularity of photoelectric engines, the market of linear ICs has gradually increased, and the electrolytic capacitor-free solution directly refers to traditional capacitors, which poses a great challenge to electrolytic capacitor companies. Will electrolytic capacitors gradually fade out of the market in the future?

Electrolytic capacitors are still essential

In-depth understanding of Aladdin News Center shows 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 non-flicker lighting applications. "The low-frequency flicker caused by the high ripple current brought by no electrolytic capacitors will cause discomfort to human eyes or physiological." said Tan Chao, R&D manager of Guangdong Kegu Power Co., Ltd.

Guo Junxiong, business development manager of the LED Power Supply Division of FSP Co., Ltd. believes that the advantages of electrolytic capacitors lie in high capacitance and low cost. Although the use conditions are limited, they can still meet the needs of most indoor commercial environments. "In the absence of other new materials to replace, there is still a need for it."

As a low-cost, high-energy-density energy storage element, electrolytic capacitors play an important role in power supply design. Although electrolytic capacitors are 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 capability and the deterioration of electrical technical indicators. These problems can be solved by technical means, but the cost of the power supply will also be significantly increased, and the cost performance will be reduced accordingly.

Zhang Weili, manager of the Marketing Planning Center of Inventronics, concluded, "In the future, electrolytic capacitors will still exist in mainstream LED power products with medium and high power for a long time; In high-end applications of reliability, electrolytic-free designs may be popular. Of course, willingness to sacrifice some technical performance such as power factor or LED ripple current in exchange for low-end applications without electrolytic capacitors is another matter.”

Chen Hao, director of electronic products of Maoshuo, believes that in the future, electrolytic capacitors will still have an irreplaceable role in specific applications such as energy storage, filtering, coupling and output smoothing. For example, in the fields of power adapters, car charging piles, inverters, etc., electrolytic capacitors are the essential main energy storage devices.

While affirming the existence value of electrolytic capacitors, power supply companies also put forward higher technical and performance requirements for them, such as small size, large capacity, low ripple current, long life, and increased operating temperature.

"Electrolytic capacitors need to improve the resistance to ripple current without reducing reliability and life, which helps to reduce the size and cost of switching power supplies. In addition, the filtering effect and resistance of electrolytic capacitors to high-frequency ripple The overvoltage capability also needs to be improved." Zhang Weili expressed the requirements for the improvement of electrolytic capacitors by power supply companies.

Peng Xihe, vice president of research and development of MEAN WELL (Guangzhou) Electronics Co., Ltd. believes that the quality of electrolytic capacitors is first and foremost controlled, and then is the breakthrough in characteristics, "This requires electrolytic manufacturers to carry out strict quality control of products, but at present they can seriously There are not many manufacturers who make capacitors anymore.”

The Breakthrough of Electrolytic Capacitors

The pressure of the era of meager profits, the still many criticisms of 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 launched solid-state 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 circuits. However, due to the high price, the current market of this product is mainly positioned in the consumer power supply and communication power supply market, and in the LED field, it is mostly used in the outdoor field with harsh use conditions.

"This product will be the future development direction of aluminum electrolytic capacitors, and the market has broad prospects, but from the current technology point of view, solid capacitors still have a long way to go to replace liquid aluminum electrolytic capacitors." Chen Zhenghua analyzed that one is due to The application range of solid-state electrolytic voltage is still limited to medium and low voltage, and high voltage still has a long way to go in terms of technology; second, the technology of liquid aluminum electrolytic capacitors is mature, which can meet the requirements of most markets, and has obvious cost advantages, especially for General lighting market, aluminum electrolytic capacitors