The LED the reliability test

The LED the reliability test

'reliability' is a time when the axis of a noun, that is the equipment, in a limited amount of period, the normal operation of the equipment probability. At present the concept of reliability has already been used in the electronic product design and development stage, the purpose is to nothing more than your products quality of design can be expected to and to meet the needs of users.

Of course, for 2008 ~ 2009 years because of global financial tsunami and the economic situation in one hundred rare patch, this time 'energy saving carbon reduction' acting as a slogan of the world and the only common pursuit of the goal, so the LED Light Emitting Diode-Light Emitting Diode-has thus become 'energy saving carbon reduction' product of The Times. As long as it is with 'light' in the relationship between the product, all the manufacturers, no need not the very attempts and LED interplanting links. For example: light, lighting, interior atmosphere lamp, billboard light, light, panel backlighting... In recent years, the development of these fast, even LED related peripheral products and the speed of development international standards set by far the unit tests and regulations, LED in the world is not yet a seems axiomatic code for the product designers LED related used, so now LED regulations on the market into schools of thought contend, their expression of the warring states.

So the author see this kind of situation, and judge in a short time should also won't have reached consensus on the results, and wants to for the majority of LED products designers with some advice, its purpose is not to call for all the rules and regulations for the LED to gave birth to, but to share personal experience in the field of in reliability, to outline born a product designer without parallel in international standard method to follow or under the guidance of, how to design for the LED products do preliminary and validation of the basic understanding of development LED products with tolerance, then improve the design quality level, improve market acceptance and reduce the risk of guest back.

The following will introduce two simple, no matter the LED to most of the form of parts or products, can make use of and follow the following pattern to achieve the basic LED products validation.

1. The product life test and verify

In the electronic industry, and to ask service life of product, it usually use three methods

(1) life Prediction method (Prediction)

Methods: according to the 217 count HDBK mil-parts (again) and the count of parts stress method (again, the principle of "stress" can be calculated using software to the life of the product.

Advantages: take short, the cost is low

Weakness: the results easy and practical product life difference greatly

(2) the method to life ()

Methods: use accelerated model (Acceleration model), to work out the accelerated factor (Acceleration) and provide real samples increase by using environment test sample measured in order to mimic product life. At present model to accelerate Arrhenius model (high temperature acceleration), Coffin-Manson model (temperature cycle acceleration) and Hallberg-Peck (humidity acceleration) the highest degree. Advantage: the results are estimated method true, the industry to accept degree is high

Weakness: the high cost and time consuming estimate method is long

(3) the market feedback method (Field pressing)

Methods: recycling product the user in the market condition of use.

Advantages: the result is real life

Faults: time and cost more difficult to obtain the use situation, market, usually only a self preservation. Brand

Three kinds of products on the method of life for life the most measured by method of industry, because it not only from the results and practical produce the gap of the faults, and it is through the measured, regardless of both parties to accept degree is high.

2. Product environmental test

The author to zero component magazine March 2009 had raised about LED related products need to implement the environmental test what project and the project simple definition. So in this about the content of the test and details in this is not travel through the jungle. But this will guide you how to use these environmental test project has reached real ascension quality level of product design.

First must yourself in the design of product to a life of analysis, the product profile in the life cycle in the environment that might be in? Users? This product attributes? Products have other special requirement? All of these factors may affect the future of the specifications of the test is in process, do not fall into the standard lost, because a good test specifications absolutely not completely from a standard completely copy into, because it is a good standard can't simulate the actual environment demand, they are in vain, for it will only waste more resources and cost. For example: LED lamps and lanterns designer to design a street lamp in the streets of Indonesia, and make use of low temperature to 40 ¡æ validation specifications, very happy to do so, because in the low temperature of the IEC advice is to 40 ¡æ. But please you recall, Indonesia is located in near the equator, belong to tropical climate, aged hot humid, how will encounter-40 ¡æ climate? So for a forever the environment to do not touch the design of the product, will only increase the design cost, because design can withstand-40 ¡æ environment LED lamps and lanterns cost must be higher than 0 ¡æ design enough against the environment.

So the author's intention is please you product designers should return to examine their fundamentals, the design of products, to do an effective will be able to meet the needs of a reliability test.

Finally, because the LED products is different from other electronic product, no matter the reliability test before and after the luminescence properties for its must do measurement, general and commonly used's calculus ball or light distribution curve, can be measured quantity is the Color of LED products (Color), Luminous flux responds as required (flux), light intensity (Luminous intensity), Color coordinates (Chromaticity coordinates), play Color sex (Color), so wavelength (the Wave length), etc., as the reliability test judgement on the basis of the results.

Related reading:
Previous:Drive and switch on the LED linear type drive
next article:With thick film technology optimization high power LED-1
Directory page:LED Information
Return top