Zhimao Electronics: Dedicated to the quality inspection of LED lamps production line to ensure product quality

[Source: "Engineering LED- Technology and Application" 12 issue of reporter / Long Zong-hui]

"The LED lighting market is still not mature, and the products with uneven quality are flooding the market, causing consumers to lose confidence in LEDs." Liao Zhixin, deputy general manager of the marketing department of Zhongmao Electronics (Shenzhen) Co., Ltd. said that the domestic LED SMEs have a large base. Many companies do not pay much attention to product quality inspection.

At the same time, many enterprises have no conception on the specific testing items of LED lamps, the specifications for the use of testing instruments, and the specific standards for marking.

According to the reporter's understanding, in order to improve the quality of LED lighting products, the relevant departments of the state have made great efforts to build LED quality inspection centers, and accelerate the introduction of national standards through market research and other means, hoping to completely change the quality of LED lamps in the Chinese mainland market.

However, according to the recent news released by the General Administration of Quality Supervision, Inspection and Quarantine, the quality problems of domestic LED manufacturers are still very prominent.

Enterprises lack professionalism in testing

Judging from the current market situation, there are few companies that perform final inspections of production lines, and fewer are strictly implemented as required. At the same time, domestic LED lighting companies are generally small and medium-sized, and many of the large enterprises are transformed from traditional lighting. There is almost no concept for the difference in quality inspection between traditional lamps and LED lamps.

“Because the company does not understand the field type and spectral correction coefficient, all LED lamps are tested by the same standard, and the quality inspection data deviation is at least 20%-30%.” Zhimao Electronics Co., Ltd. (hereinafter referred to as “Zhuo Electronics” "Li Jingwei, director of the Product Planning Department of the Integrated Systems Division, said.

It is understood that domestic LED lighting companies often give up strict product quality inspection processes in order to achieve capacity targets, or directly change the full inspection to random inspection.

“The practice of disregarding product quality neglects many variations from design to mass production.” According to Li Jingwei, the heat dissipation problem that has a direct impact on life, even if the design is perfect, can not guarantee the cooling of a single LED. In good cases, after the process integration, the original heat dissipation effect is maintained, and the overall heat dissipation performance of the LED lamp is not guaranteed.

LED lighting inspection projects are mainly concentrated in four aspects: light, machine, electricity and heat. Among them, light detection is the most complicated, and there are many influencing factors. The main measurement parameters of several LED lamps such as luminous flux, color temperature, indexing and life, IEC, Energy Star and other certification systems have put forward specific measurement methods and requirements. For example, in terms of luminous flux, ENERGY STAR certification requires a 135-180 degree light distribution for full-circumference, and the amount of light must be more than 5% of the total light output. At the same time, the measurement of light efficiency is more related to field type and spectrum. Unlike voltage and current, there is little possibility of variables.

At present, domestic LED companies generally use the integrating sphere to test the luminous flux. Strictly speaking, the integrating sphere does not guarantee a 100% perfect circle, and there is absolute unevenness in the space and field error. “In general, we choose gas lamps for test calibration, but different LED fixture types and different illumination angles have their own calibration parameters. Traditional lighting manufacturers do not understand these.” Li Jingwei said that they (traditional The luminaire manufacturer can't even understand why the integrating sphere needs correction, and it doesn't know how to correct it.

In terms of life testing, ENERGY STAR requires manufacturers to test under steady state conditions, and many companies do not know. Therefore, many LED lighting companies even buy high-end integrating spheres or other testing equipment, the test error is still around 20% -30%.

Misrepresentation floods the market

Recently, the US Department of Energy released a sample inspection result of LED lighting products. The report said that the detection defect rate is as high as 50%, and the sampling content is only for the matching of the identification and the measured content of the lamp.

Previously, a US company was also sued for the inconsistency between the logo and the measured indicators. There have also been records of similar warnings issued by 12 local LED lighting companies in Japan.

“In fact, in order to upgrade the brand, many companies often take the 'finely crafted' products for inspection and then ship them to customers with 'ordinary' products.” Liao Zhixin believes that the inspection can only indicate that the individual products being inspected meet the requirements. The requirements of the certification standard, but do not represent the quality level of the mass production products of the entire production line. "Many companies are holding a 'quality inspection report, going around the world' mentality."

Li Jingyu told reporters about his personal experience. A 6W downlight sold at a price of 70 yuan is sold by a company. The mark on the outer packaging of the product is color temperature 3000-6000k, warranty for two years, and luminous flux 630lm. According to the energy efficiency rating of the lamp, the energy efficiency of this lamp has reached the A++ standard, and the price of only 70 yuan can have such high energy efficiency. It is really eye-popping, because the price of the lamp that meets this energy efficiency standard is basically several times the above price. the above. At the same time, the 3000-6000K color temperature parameter of the product identification belongs to the range value. If the consumer buys ten lamps, the color temperature is difficult to ensure the same. "There are a few companies that have problems with the logo, and there are cases where the lm/W and lm conversion results are different."

In addition to the identification of fraud, some small domestic LED lighting companies even marked the quality commitment of 3-5 years replacement. When consumers took the light bulb to replace it, they found that the company had disappeared. “We later found out that this company has changed its face to another brand.” A consumer with the above experience told reporters.

For more information, please refer to "High - tech LED - Technology and Application" 1 February issue