High brightness light emitting diodes (HB LEDs ) combine high output, high efficiency and long life. Manufacturers are developing devices that can achieve higher luminous flux, longer life, richer colors, and higher luminosity per unit of power. To ensure performance and reliability, accurate, cost-effective testing must be performed at every stage of production. Figure 1 shows the electrical I-V characteristic of a typical diode. Although a complete test procedure can include hundreds of points, probing for a limited sample is generally sufficient to provide good value. Many HB LED tests require a known current source to drive the device and measure its voltage accordingly, or vice versa. Simultaneous signal sources and measurement functions that can be synchronized can speed up system setup and increase throughput. Testing can be done at the die level (wafer and package) or module/subassembly level. At the module/subassembly level, HBLEDs can be connected in series and/or in parallel; therefore, higher currents are typically required, sometimes up to 50A or higher, depending on the application. Some die-level tests use currents in the range of 5 to 10 A, depending on the die size. Shenzhen Jiesai Electric Co.,Ltd , https://www.gootuenergy.com
Figure 1. Typical HBLED DC I-V curve and test points
February 04, 2024