The Influence Of High-power Flip-chip And Its Fluorescent Materials On The Light-emitting Characteristics Of The Device

Light-emitting diode(LED)products have been recognized as an alternative to traditional lighting technology in many lighting applications.LED has the advantages of high electrooptical conversion efficiency,energy saving,environmental protection,high brightness,long life,small size,etc.,making it play an increasingly important role in many application fields.The LED flip chip is directly eutectic on the ceramic PCB substrate,and then a layer of phosphor is sprayed or a fluorescent ceramic sheet is attached to obtain a ceramic packaged white LED,which is currently one of the mainstream solutions for high power density LED devices.In this paper,the high-power Ga N-based flip-chip blue light chip packaged by ceramic eutectic is the research object,and the uniformity of high-power flip-chip mesa light emission and the influence of electrode isolation area on the light emission uniformity of the mesa and the effect of phosphors of different materials on LED photoelectricity are studied The influence of parameters.The main research content and conclusions of this article are as follows:(1)The uniformity of light emission on the top surface of high-power-density LED devices with ceramic packages is a key indicator of this type of device when working at high currents.This paper on the aluminum nitride ceramic substrate size of 3.5 mm × 3.5 mm gold-tin eutectic of 75 mil × 72 mil blue high-power LED flip chip,and then were made into white light emitting device and blue light components.The uniformity of micro-area luminescence on the top surface of these devices was also studied.The results show that when the current is less than 4 A,the light intensity distribution on the top surface of the blue device is uniform,and the uniformity is less affected by the N electrode hole and the electrode gap.When the current is 4 A to 8 A,the light intensity distribution on the top surface of the blue light device is uneven.The light passing through the test area of the N electrode hole is stronger than the light intensity of the test area between the electrode holes.The light intensity of the electrode gap area is the lowest,which is far from the N electrode hole.The farther the test point,the lower the light intensity.The overall light intensity of the blue light device reaches saturation at 8 A,but the degree of light saturation and peak wavelength of different micro-area varies with the current change;when the white light device is at a current of 0-4 A,the light intensity distribution on its top surface is uniform.(2)Experiments on flip-chip blue ceramic packaged LEDs with different fluorescent materials,through experiments with independent variables as currents and different fluorescent materials,comparative analysis of some optical characteristics of the samples,and research on different currents,different fluorescent materials,and the same fluorescent material Changes in optical performance parameters caused by different color temperatures.According to the experimental results,fluorescent ceramics can effectively increase the light saturation current threshold of LED devices when different fluorescent materials are used.Among them,the effect of high color temperature fluorescent ceramics is more significant,the color temperature is more stable,but its color rendering is poor.However,attaching fluorescent ceramics to integrated devices is not as effective as single-core high-power LED devices in improving the optical characteristics of the devices.This research can provide certain experimental basis and data support for the research and development of high-power density Ga N-based blue LED devices.