LED Introduction
LED (Light Emitting Diode), also known as light emitting diodes, is the use of solid-state semiconductor chips as light-emitting materials. When a forward voltage is applied across the semiconductor, carriers in the semiconductor recombine, emitting excess energy and causing photons to emit visible light and far-infrared light. Near-infrared light.
LED is a new type of solid-state light source that has shown its own excellent results in special fields. Various types of LEDs, products that use LED for secondary development, and products supporting LEDs are developing rapidly. New products are on the market and have been developed. Become a lot of new industries. Looking forward to the future, we also look forward to further improvement.
What are the main application points of infrared thermal imager in the LED industry?
In fact, the actual lifetime of an LED is often inversely proportional to the operating temperature. For example, the LED lifetime is 10,000 hours at 74°C, 25,000 hours at 63°C, and 50,000 hours at less than 50°C. The fundamental reason is that the photoelectric conversion efficiency of LED is extremely poor, only about 15% to 20% of the electrical energy is converted into light output, and the rest are converted into heat energy. Therefore, when a large amount of high-power LEDs are used in a module, it is applied to high brightness. During operation, these very poor conversion efficiencies will cause major problems in thermal processing.
Infrared thermal imaging cameras not only play a role in the development process, but also can be applied to product quality management.
1 R&D: Mainly for LED module driving circuit (including power supply), light source semiconductor heat distribution analysis, and light failure test.
a) LED module driver circuit
In the development of LED products, an engineer is required to design a part of the driver circuit, such as a rectifier circuit module. Using infrared thermal imaging cameras, engineers can quickly and easily find the temperature anomalies on the circuit, to facilitate the circuit design.
b) LED light source semiconductor chip heating
Using an infrared thermal imager, engineers can analyze the temperature and temperature distribution of their chips during operation by using the heat-generating infrared heat map of the light source semiconductor chip. On this basis, the purpose of improving the life of LED products can be achieved.
c) Light decay test
The decline of LED products is the signal attenuation of light in transmission, and at this stage, LED manufacturers in the world have made LED products with different levels of light decay. High-power LEDs also have light decay, which has a direct relationship with temperature. It is mainly determined by the wafer, phosphor and packaging technology. At present, the decline of white LEDs in the market may be one of the most important issues for civilian lighting.
2 Quality Management
a) Semiconductor Lighting: Blown Bulb Uniformity
The infrared thermal imager captures the process of blowing bubbles in the production line, corrects the parameters, and improves the rinsing process, which can effectively increase the product yield and reduce costs.
b) Temperature before LED inspection chip package
Detection temperature before LED chip package can avoid abnormal temperature after packaging, reduce scrap rate. At this stage, the hand cannot touch the surface, and the infrared camera can help the customer to find the problem here as a pipeline inspection tool.
c) LED finished display boot test
After the completion of the LED display, the final acceptance is required. Through different colors of the test to see whether the screen meets the requirements of delivery, most companies do not have this process. With the use of an infrared thermal imager, it is possible to improve product testing standards for manufacturers and improve product quality.
Typical customers
Dawn photoelectric, Philips lighting and so on.
The unique role of infrared camera
Before using infrared thermal imagers, LED product companies have not been a good solution to this problem. The infrared camera can play a unique role:
1 When the target is detected by an infrared thermal imager, there is no need to power off and the operation is convenient. At the same time, the non-contact measurement makes the original temperature field undisturbed; the reaction speed is faster and less than 1 millisecond.
2Fluke infrared thermal imager IR-Fusion technology: Users can use Fluke's patented IR-Fusion technology to capture infrared images in addition to capturing a visible light photo and fuse them together to help identify and locate the first time. malfunction.
What problems might you encounter while shooting?
Due to the small observation target, when using a 160×120 thermal imaging camera, it may be difficult to find an accurate point of failure. We need to replace the 320×240 thermal imaging camera (even if the lens needs to be replaced) for detection.
How can I shoot high quality infrared thermal images?
When shooting with an infrared camera, to get an excellent infrared heat map, we recommend:
1 If there is a need to distinguish small temperature differences, try to select an infrared thermal imager with high thermal sensitivity;
2 First measure the temperature range with automatic mode; then manually set the level and span, set the temperature range to the minimum, and include the previously measured temperature range