Analysis of basic verification methods for LED products

First of all, we must analyze the life profile of the product we designed. What is the environment that this product may exist in the life cycle? What are the users? The properties of this product? Are there any other special requirements? Are these factors likely? Influencing the future is the specification of the test, and do not fall into the norm of the process in the process, because a good verification specification is definitely not completely copied from a certain specification, because even the best specification can not simulate the actual environmental requirements. That is just a loss, it will only waste more resources and costs. For example: The designer of LED lamps designed a street lamp for use in the streets of Indonesia and set a verification specification of -40 ° C. It is very happy to do it because the recommended low temperature in the IEC is -40 ° C. But please think back, Indonesia is located near the equator, it has a tropical climate. When it is hot and humid all year round, how can it encounter a climate of -40 °C? Therefore, designing a product that never touches the environment will only increase the design. Cost, because the cost of LED luminaires designed to withstand -40 ° C environment must be higher than the design is designed to withstand 0 ° C environment.

Therefore, please let the product designers return to the fundamentals, and carefully review the products designed by them, in order to achieve an efficient and reliable verification of the actual requirements.

Finally, because the LED products are different from other electronic products, regardless of the reliability before and after verification, the luminescence characteristics must be measured. Generally, the calculus ball or the light distribution curve meter can measure the color of the LED products. Temperature), Luminous flux, Luminous intensity, Chromaticity coordinates, Color rendering, Wave length, etc., as the basis for reliability verification results.

2. Product life verification

In the electronics industry, in order to claim the life of a product, three methods are usually used.

(1) Life Prediction Method (Prediction)

Method: According to MIL HDBK 217 Part Count and Part stress principles, software is used to calculate the life of the product.

Advantages: Short time and low cost

Disadvantages: The result is very different from the actual product life

(2) Lifetime measurement method (Demonstration)

Method: Using the Acceleration model to obtain the Acceleration factor and provide the actual sample, the sample was measured by an environmental test simulator to obtain the product life. At present, the acceleration model adopts the highest Arrhenius model (high temperature acceleration), Coffin-Manson model (temperature cycle acceleration) and Hallberg-Peck (humidity acceleration).

Advantages: The result is more realistic than the prediction method, and the industry is highly accepted.

Disadvantages: Higher cost and time-consuming than estimated method

(3) Field return method (Field return)

Method: Recycle the use of product users in the market.

Advantages: The result is equal to the real life

Disadvantages: Time and cost are longer, market usage is difficult to obtain, usually only the brand field self-preservation

The above three methods for determining the life of the product are adopted by the industry at the most, because it can not only eliminate the shortcomings of the result and the actual difference, but it is obtained through actual measurement, regardless of the high acceptance of both buyers and sellers.