| With the development of science and technology,people's awareness of environmental protection is gradually strengthened,and the government advocates energy saving and emission reduction in daily life.Although the new high-power LED lamp has the advantages of energy saving and high luminous efficiency,in the production process,because the viscosity of the encapsulant is too high,the yield rate is low.Therefore,it is necessary to find a new processing method of the encapsulant,which has effectively reduced The adhesive viscosity of the package does not change its physical properties.Related studies have shown that ultrasonic processing of epoxy resin glue can effectively reduce its viscosity without changing its inherent physical properties;according to this idea,this paper proposes the use of ultrasonic processing as an epoxy resin and phosphor for LED packaging materials.In the mixed glue solution,the ultrasonic parameters were changed by the single variable m ethod through experiments,and the mixed glue solution was processed by the ultrasonic vibrator to study the effect of the ultrasonic processing time,the ultrasonic power,the ultrasonic frequency on the viscosity of the mixed glue,and the jet dispensing process.In order to complete the experiment successfully,the corresponding power ultrasonic power source was designed.In the design part of the power ultrasonic power supply,the overall scheme of the ultrasonic power supply hardware system was designed.Starting from the functional requirements of the power adjustment and frequency automatic tracking of the ultrasonic power supply,a power control,high frequency inverter,single-chip microcomputer control,and matching network were designed.The ultrasonic power supply hardware system composed of four functional modules,based on the hardware,wrote a software program composed of three functions modules: LCD display,knob encoder interrupt adjustment,and constant voltage control.Finally,a frequency tracking system was created.Function,output power 300 W,ultrasonic power at 50 k Hz to 70 k Hz.In the ultrasonic treatment of the mixed glue experiment and the viscosity measurement section,an overall solution for the viscosity measurement experiment was formulated;the existing ultrasonic power supply with a frequency of 24 k Hz and a home-made ultrasonic power supply with a frequency of 50 k Hz to 70 k Hz were used to drive the corresponding ultrasound.The vibrator is used to process the mixed glue liquid used in the LED package;the rotational viscosity of the glue under the influence of three different ultrasonic parameters of the ultrasonic power,the ultrasonic frequency,and the ultrasonic treatment time is measured by a rotary rheometer;the dispensing glue is sprayed by a spray dispenser,Using a high-speed camera to record the dynamic change of the shape of the glue during the spraying process;finally,the diameter of the droplets dropped on the substrate is counted,and the consistency of the glue b efore and after ultrasonic processing is analyzed through data comparison.This study found that,as the LED encapsulated epoxy resin and phosphor hybrid glue,the viscosity decreased significantly after ultrasonic processing;when the ultrasonic processing glue was sprayed,the broken glue was crisp and uniform;the diameter of the glue droplet The data show that the consistency of the glue after ultrasonic processing has been greatly improved;in the three parameters of ultrasonic processing time,ultrasonic frequency and ultrasonic power,ultrasonic processing time and ultrasonic power to reach the viscosity of the glue is significantly better than the ultrasonic frequency The effect of the ultrasonic frequency on the viscosity of the glue basically disappears under high shear rate.Ultrasonic processing of the mixed glue used in the LED package can effectively reduce the viscosity of the glue,and thus the process and quality problems of the sprayed glue in the LED packaging process due to the high viscosity of the mixed glue at a relatively low temperature,Provides an effective solution. |
