作者：Blade

How to promote an aging test for led yard lighting

How to promote an aging test for led yard lightingAging is an important guarantee of the reliability of electronic products, is a production of the last essential step. LED products can enhance the performance of aging and contribute to the late stage of the performance and stability. Led yard lighting aging test in product quality control is a very important part, but often neglected in many cases, can not be correct and effective aging. Led yard lighting aging test is based on the product failure rate curve of the bathtub curve characteristics and countermeasures taken, in order to improve the reliability of the product, but this method is not necessary, after all, the aging test at the expense of the life of a single LED products for the price.

 

Led high bay lights’ aging test, including the constant current aging and constant aging. The constant current source is the current constant at any time. Frequency problem, it is not constant current. It is AC or pulsating current. AC or pulse current source can be designed to be valid value is constant, but this power can not be called “constant current source. Constant current aging is most consistent with the operating characteristics of the LED current is the most scientific of the LED aging; overcurrent impact of aging is also factory using the latest means of an aging through the use of adjustable frequency, current adjustable constant current source such aging in a short period of time in order to judge the quality of the LED life expectancy, and can pick out a lot of conventional aging can not be singled out hidden led yard lighting.

New market strategy of solar led street lighting

 

New market strategy of solar led street lighting

 

LED market analysis data show that in 2011 the global solar led street lighting market value reached $ 16.6 billion, the scale of the whole industry is still expanding. The entire product system, more than 60% of the production of market failures and more than 70% of rework due to device failure, but most companies have failed to adopt systematic electronic reliability engineering methods to solve, leading to product quality is not high, life is not long. China’s lighting industry has been price and other factors, is obviously insufficient to extend the life of the product design. In view of this, it can be predicted that in the development process of the solar led street lighting industry, how to assess and improve the service life of LED products will become the subject of a new round.

 

In the heat, the traditional way is to add a heat sink. Optimize the design of LED products with the tapered shape designed to achieve. First, the cone can form a variety of ventilation ducts to help the bulb to transfer heat, cooling effect. Second, a reasonable choice of devices, the test excluding unqualified or early failure help to improve the reliability of the product. In addition, a reasonable process improvement also help to improve the life of the product. Simply put, is to reduce the stress on the device through standard and reasonable process, thereby strengthening the product performance and improve the durability of the led high bay products.

 

In general, improve product reliability can effectively improve product quality, and produce more cost-effective for companies to create more economic benefits.

Improved aging test for solar led street lamp

 

Improved aging test for solar led street lamp

 

Aging is an important guarantee of the reliability of electronic products, is a production of the last essential step. LED products can enhance the performance of aging and contribute to the late stage of the performance and stability. Solar led street lamp aging test in product quality control is a very important part, but often neglected in many cases, can not be correct and effective aging. Solar led street lamp aging test is based on the product failure rate curve of the bathtub curve characteristics and countermeasures taken, in order to improve the reliability of the product, but this method is not necessary, after all, the aging test at the expense of the life of a single LED products for the price.

 

Solar led street lamp aging, including the constant current aging and constant aging. The constant current source is the current constant at any time. Frequency problem, it is not constant current. It is AC or pulsating current. AC or pulse current source can be designed to be valid value is constant, but this power can not be called “constant current source. Constant current aging is most consistent with the operating characteristics of the LED current is the most scientific of the LED aging; overcurrent impact of aging is also factory using the latest means of an aging through the use of adjustable frequency, current adjustable constant current source such aging in a short period of time in order to judge the quality of the led high bay life expectancy, and can pick out a lot of conventional aging can not be singled out hidden LED.

How to create the high quality led lights

 

How to create the high quality led lights

 

Most lighting designers believe that the quality of all LED products are the same. However, many LED manufacturers and suppliers, Asian manufacturers to low-cost global supply LEDs. Surprisingly, only a small part of these manufacturers to create high quality led lights. For applications that only used as a simple indicating the role of the low quality of the LED is sufficient to meet the requirements. However, in many areas of the requirements of consistency, reliability, solid-state instructions or lighting must be of high quality led lights, especially in harsh environments, such as highways, military / aerospace, and industrial applications.

 

In the New York subway stations and other environmental, safety requirements are very demanding, the led high bay lights must meet the high quality requirements of the fundamental factors.

 

Distinguish between the level of LED quality factors? How to tell the difference between the two LED’s? In fact, high-quality LED chip start until assembly is complete, during which there are many factors to consider. Tier-One, the LED manufacturing company capable of producing excellent indicators of the same wafer is to start from the high-quality LED manufacturing materials, enough to make a good chip. Determine the conditions of the LED performance, the chemical materials used in wafer production process is a very important factor.

 

A 2-inch wafer can be cut out more than 6000 high quality led lights chip, there is only individual chip performance overall. A good chip manufacturer makes chips in the difference of color, brightness, and the voltage drop is very small. When the LED chip package is completed, many of their performance, there may exist a great difference, such as perspective. In addition, the impact of packaging materials is quite large, for example, silicone epoxy performance.

Heat dissipation for high power led applications

 

Heat dissipation for high power led applications

 

High-power LED products and devices in the application process, thermal, electrostatic protection, welding has a great impact on the need to attract the customers of the application side attaches great importance to its characteristics.

 

Semiconductor light-emitting diode chip technology limitations of LED photoelectric conversion efficiency remains to be improved, especially in high power led applications, because of the higher power, about 60 percent more electrical energy into heat release (along with the development of semiconductor technology photoelectric conversion efficiency will be gradually increased), which requires the end-customer to do when the application of high-power LED products heat work to ensure the normal work of the high power led applications.

 

1. Effective cooling surface area:

 

1W high power led high bay white (other colors are basically the same) Division I recommended to the sum of the effective cooling surface area of the heat sink ≥ 50-60 square centimeters. 3W products, recommended the sum of the effective cooling surface area of the heat sink than 150 square centimeters, as the case of higher power and test results to increase as much as possible to ensure that the heat sink temperature does not exceed 60 ℃.

 

2. Connection method:

 

Please ensure that the two contact surfaces smooth connection of high power led applications substrate and heat sink, good contact, to enhance the degree of integration of the two contact surfaces, it is recommended that the surface coating layer of thermal grease in the bottom of the LED substrate or heat sink (thermal grease thermal conductivity the ≥ 3.0W/mk), thermal grease evenly coated, amount, and then screw press fit fixation.

How to improve the reliability of LED intelligent lighting system

 

How to improve the reliability of LED intelligent lighting system

 

LED drive power of the low life expectancy is an important reason is the lack of the life of the drive power required for aluminum electrolytic capacitors, mainly due to working long hours and led lights inside the ambient temperature is high, resulting in aluminum electrolytic capacitors quickly consumptiondry, life is much shorter, generally only work about 5,000 hours. The LED light source life is 50,000 hours, the working life of aluminum electrolytic capacitors has become a life short rib led drive power of LED intelligent lighting system.

 

Now some vendors in order to solve this problem, the invention of aluminum electrolytic capacitors, LED drive power program. But not all of the LED drive power suppliers are in favor of this approach. Chen Rong said: “At present, the LED drive power production, there is no a is a non-electrolytic capacitor driven program, because without it, then a lot of test criteria to pass EMI testing and flicker-free test.”

 

While the aluminum electrolytic capacitors, LED driver power of led high bay lighting system is usually more of these tests, if you replaced the film capacitors and ceramic capacitors or tantalum capacitors, the situation how? Film capacitors to achieve the same capacitance (typically 100-220uF), the volume will be enormous, and the cost is too high, the general capacity of the ceramic capacitor is too small, such as multiple ceramic capacitors to achieve such a large capacity, footprint and cost too much, and tantalum capacitors to have such a large-capacity.

 

Many suppliers claim that the non-electrolytic capacitors LED intelligent lighting system program, it may just get rid of the aluminum electrolytic capacitor of the AC input, constant current output of aluminum electrolytic capacitors should be difficult to remove or replace.

PESD for LED outdoor led spotlights

 

outdoor led spotlights

 

LEDs are semiconductor devices, are more sensitive to static electricity to prevent static electricity and eliminate static electricity work to do, especially for white, green, blue, purple outdoor led spotlights.

 

1. Generation of static electricity:

 

① friction: in everyday life, any two objects of different materials contact after separation, you can generate static electricity, while the most common way to generate static electricity, friction power. The better the insulation of the material, the more likely friction call. In addition, any two different substances, objects in contact after separation, can also generate static electricity.

 

② induction: a conductive material, due to the electron energy in the surface of the free flow, if placed in an electric field, due to same-sex repulsion, opposites attract, the positive and negative ions will be transferred on its surface will produce charge .

 

③ conduction: for electronic contact with the electrically charged objects in its surface free flow of conductive material, the charge transfer.

 

2. The hazards of static outdoor led spotlights:

 

① heat generated due to the instantaneous electric field or current, the LED local injury, the performance of the rapid increase in leakage current can still work, but the decrease in brightness, life impaired.

 

② electric field or current destruction of the insulation layer of the LED, the device does not work (completely destroyed), dead lights.

 

3 ESD and the elimination of measures:

 

All employees have direct contact with the led high bay lights for the entire process do to prevent and eliminate static electricity measures, mainly

 

①, workshop laying anti-static floor and good grounding.

 

②, the table to prevent static table, the production machine well grounded.

 

③, the operator to wear anti-static clothing, with anti-static

The application range of high power led technology

 

The application range of high power led technology

 

High power led technology in the oil field, petrochemical, railway, mining, military and other special industry, stage decoration, urban landscape lighting, display and sports stadiums and other special lamps have a wide application prospect.

How it works:

 

Light-emitting diode (LED) is a solid device for a can convert electrical energy into light energy, its structure is mainly composed of chips of the PN junction electrode and optical systems. The basic working principle of the high power led technology is an electro-optical conversion process, when a forward bias is applied to both ends in the PN junction, PN junction barrier to reduce the spread of P region of positive charge will be N region, the N-zone electronic the proliferation of P region, the formation of non-equilibrium charge accumulation in the two regions. PN junction due to the relative instability of minority carriers generated by current injection, injected into the non-equilibrium holes in the valence band to the conduction band electron recombination in which the excess energy will be in the form of light radiate outward. electrons and holes, the greater the energy difference between the photon energy is higher. Energy steps of different sizes, frequency and wavelength of light is different, the corresponding color of the light will be different.

 

High power led technology is a phase for low-power LED lamp (compare high power led high bay lights and low power led bulbs), the higher the power of high-power LED lamp, the brightness is brighter, higher prices. Small power LED lamp rated current is 20mA, rated current higher than 20mA of almost all can be regarded as high.

The third-party testing for high power uv led suppliers

 

The third-party testing for high power uv led suppliers

 

In order to eliminate the injustice of the test, many companies are entrusted to a third party to test the LED assembly and circuit structure. LED devices may be tested in the harsh environment, or use a few weeks. During the test, at the same time the pressure, temperature cycling, fixed voltage / change current fixed / change test, test to determine whether the high power uv led suppliers to meet the application requirements in other harsh environmental conditions.

 

Accelerated life cycle testing is a key test to avoid failure in special applications. The test helps to ensure that screen out those expectations at least for 100,000 hours, but only work 1000 hours in advance of LED failure. This situation may arise because of the low-quality LED will reduce the brightness after 1000 hours of work. In fact, if a lower-quality high power uv led suppliers have a higher drive current, at an early stage is high quality LED light, however, the excessive current causes the LED heat too fast, the end result is the brightness dimmed or burned.

 

In addition, the assembly technology to some extent on the LED performance than the chip itself is also a big example. The design engineer should ask for the reliability of the specifications of LED to LED suppliers, and the LED assembly and testing to ensure that the relatively high brightness is indeed better. Some excellent led high bay suppliers to ensure the reliability of the LED assembly technology for three years or longer, and can further provide the ultimate LED products, including the appropriate design with high quality LED and for special applications.

The products supporting capacity of household led lights

 

The products supporting capacity of household led lights

 

In addition to discrete LEDs, LED assembly and power supply for its performance, brightness and color index have a very significant impact. Due to ambient temperature, operating current, the circuit structure, voltage spikes and environmental factors and so can affect the LED performance indicators, the appropriate circuit design and assembly is critical to protect the LED and to ensure performance. Household led lights manufacturers use a variety of techniques and different materials to design the circuit structure and assembly, in most cases, the LED assembly on the experience level of the difference will cause the LED in the same application there are differences in overall performance and reliability.

 

With the rapid growth of the household led lights needs, serve the global market manufacturers and assembly plants also increasing rapidly. It is regrettable that the surge in the support of manufacturers is not only a large number of low-quality LED packaging and LED design engineers to experience a relative shortage of Therefore, in addition to the existing experience and accurate screening LED suppliers, OEMs must also examine their circuit design and assembly technology to ensure that it meets the design specifications, and design to provide sufficient cooling capacity, because the cause of led high bay lights failure and performance the inconsistency of the main factors is overheating.

 

Excellent household led lights manufacturers can not only create high-quality chips, but also has the ability, depending on the LED color, brightness, voltage drop and perspective of its classification packaging. The high quality LED suppliers to provide customers products with consistent operating characteristics, while lower-quality LED suppliers only provide LED similar to the “mixed”.