日期：2012年7月9日

How to make high quality LED chips (2)

Except individual LED chips, LED Lights packaging and LED power supply can impact significant influence on their capacities, brightness and color. We defined them as internal factors. External factors are mainly from circuits and other electronic components. Since working temperatures, current, circuit construction, voltage peak can also affect the performance of LED chips. Proper circuit design and assembly is the key to protect the LEDs and ensure their performance. During the packaging process, even different assemblers with different working experience will cause the non-uniformity.

 Except individual LED chips, LED packaging and LED power supply can impact significant influence on their capacities, brightness and color.

With the rapid development of LED demand, the global-oriented LED chip suppliers and packaging factories are booming simultaneously. Unfortunately, the over-booming trend made many manufacturers choose to use low quality LED chips to reduce cost. Besides, their LED packaging designers and engineers are usually lacking of working experience. Most OEM producers have no capability to establish their own LED chips sections. Replying on other LED chip suppliers is their single solution. Experienced producers know how to choose right suppliers and also conduct a series of testing for LED packaging and circuit structure.

 

In order to eliminate the injustice during the testing, many companies chose to employ a third party to test the quality of LED street light chips. In the period of testing, randomly chosen LED chips will be gathered together into some specific testing rooms. These LED chips will be continuously working for several weeks in the harsh conditions, including pressure test, temperature test, fixed/flexible voltage test, fixed/flexible current test, etc. A large amount of data should be recorded before and after the testing. The three major parameters of LED: light intensity, color, potential drop should keep in record during the entire testing process. Only high quality LED chips can survive from it.

 

Accelerated life cycle testing is a key point to avoid failure in special applications. This test can help eliminating those LED chips which has an estimated service life more than 100000 hours but will be failed after 1000 hours work. This happens often. The light intensity of low quality LED chips (or high quality LED chips with unreasonable assembling) will drop dramatically after 1000 hours work. In fact, low quality LED tubes chips using higher driving current are more brightness than high quality LED chips in the early stage of service. However, continuously working in high temperature may cause huge damages to them.


How to make high quality LED chips (1)

Most LED lighting designers believe that all LED chips have same quality. However, there are hundreds of thousands of LED chip providers or LED chip manufacturers. Asian LED Lights manufacturers can produce the cheapest LED chips all around the world. But, to buyers’ astonishment, only very few of them can actually make high quality LED chips. Low level LED chips can only be competent in small lamp market. But in other application area, in which LED products should be used under severe environment (expressway, military/aviation, other industry), high quality LED chips are necessary.

 Most LED lighting designers believe that all LED chips have same quality. However, there are hundreds of thousands of LED chip providers or LED chip manufacturers.

For new comers in LED industry, how to judge the quality of LED products became one of the must-to-be-learned subjects. In fact, choosing high quality LED chips is the first step. Currently, the internationally recognized best LED chip manufacturer is CREE. Chips made by CREE have a common property of high lighting efficiency. Compare with other LED chips with the same power consumption, like Epistar, SAMSUMG, CREE chips will have more than 5%-10% luminous flux. And also, CREE chips have less light attenuation, which means, the actual service life of their chips is longer than the estimated 50000 hours.

 

If taking chip materials and manufacturing process into account, the most advanced wafer fabrication process must be the essential point. A 2-inch wafer can be cut into more than 6000 LED chips. Using one wafer, a good manufacturer can limited the differences of chips within a very slight region in almost every aspect (chip color, brightness, voltage drop). The differences can only be generated during the packaging process. Low quality LED chips will have huge differences in properties during the chip-cutting process, not to mention the packaging process. Thus LED chips generated by small factories are kind of mixtures without any classifications.

 

Best LED chip manufacturers not only produce high quality LED chips, but also perform classified packaging according to basic LED chip parameters: color, brightness, potential drop, and optic angle. A good LED street light chip suppliers will provide their customers with unified products (with much similar basic parameters).

 

In application area which high quality chips were required, like boundary lights on the airport runway, must reach FAA level certificate. In order to avoid significant accidents, mix-packaged products with much worse uniformity cannot be used.


Which part of the LED lighting industry are making money

From the current market trend, the price war has begun. In particular, after the production of LED lighting and famous Zhongshan large-scale penetration of LED lighting, the competition becomes more intense. Low price record has been renewed. We can only rely on the number of spell profits. As far as I know, the higher corporate profits only have few products lines. But more products within a single series, the quality of the high-end line, mainly for foreign markets.

How is the profit for LED Lights foreign trade?

Current of the lamp price of foreign markets decline, for example, 18W LED fluorescent tube in early is 240-280yuan/piece, and now has dropped to  210-230yuan/piece. European market is relatively better, but Africa and Asia is relatively low. Such difference has created various led lighting industry business development ideas are different, others insist that the route of the high price of higher quality, some choose a low price route.

Which kind of light is more expensive?

Now the most expensive products are the demanded products such as led lighting industry fluorescent lamp, LED bulb lamp, LED spotlight. Because the using amount of these lamps are huge, an office space raging from several thousand to as many as tens of thousands of 10 hours a day. According to the lights count, all-day power consumption is still very alarming.  Like LED lamps for light lamps, LED interior lighting home light market has not to the extent of large-scale outbreak. First, this lamp usage as LED fluorescent tube, the second is the high price of the products. Another is the LED glare problem. The above problems have constrained its growth rate, and large-scale replacement still need time.

If you want to make lighting foreign trade, where the technology should pay attention to?

A lot of led lighting industry wanted to foreign markets, foreign markets, particularly stringent requirements on energy saving and environmental protection, while the LED is the best alternative for energy saving and environmental protection. Many companies for short-term profits. Do everything possible to save material costs, this resulted in the samples and mass production of great hair.