Preparation Of Benzocyclobutene Fluorescent Resin And Packaging Application Of LED

Light Emitting Diodes(LEDs),as the fourth generation solid state lighting sources,have become the most widely used lighting equipment today due to their advantages such as long lifespan,low energy consumption,high efficiency,and environmental friendliness.Therefore the research on white LEDs is also becoming increasingly important.At present,the main way to achieve white light commercially is through the combination of blue light chips and yellow fluorescent materials.However,there are problems such as poor color saturation and chromatic coordinate drift,which limit its application in areas with high color rendering requirements such as indoor lighting.In addition,ultraviolet chips can be combined with red,green,and blue fluorescent materials to obtain white light with low color temperature and good color rendering,which has the opportunity to be widely applied in the field of indoor lighting.Benzocyclobutene(BCB)resin not only has reliable thermal stability and film forming performance,but also has characteristics of ultraviolet absorption and blue light emission,good fluorescence transfer efficiency,and other advantages.On the one hand,it can effectively encapsulate other fluorescent materials;On the other hand,the appropriate viscosity of BCB resin is not only conducive to dispensing and coating,but also can be directly used as a remote membrane fluorescent packaging after thermal curing.Based on this,this article prepared BCB fluorescent resin with orange red and turquoise green luminescence,and prepared LED light sources with warm white emission by mixing the two resins.This provides a theoretical basis for the structural design and performance research of BCB fluorescent resin,and can also provide a certain theoretical reference for other packaging materials with considerable scientific problems.(1)Perylene-3,4,9,10-tetracarboxylic acid(PDI)and 3,5-dibromoaniline were used as raw materials to prepare perylenimide compounds(TBr-PBI)through amideation reaction,and then Suzuki coupling reaction with 1,4-phenyldiboric acid to prepare perylenyl polyporous organic polymer(PBI-POP).Then mixed with divinylsiloxane dibenzocyclobutene(DVSBCB)and prepolymerized,obtaining PBI-POP/pre-p-DVSBCB resin with orange red luminescence,encapsulating 365 nm ultraviolet LED chips.The experimental results show that in mesitylene,the maximum emission wavelength of PBI-POP is 580 nm and the maximum absorption wavelength is 536 nm.PBI-POP/pre-p-DVSBCB resin was used to package LED chips,resulting in an orange red LED light source with a main wavelength of 597 nm,chromatic coordinates of(x=0.61,y=0.38),and an optical efficiency of 1.1 lm/W,which has low color temperature(1359 K),high color purity,and no blue emission.This research work has certain significance for further constructing ultra-low color temperature candlelight LED.(2)1,3,6,8-tetrabromopyrene(TBr-Py)was synthesized from pyrene and bromine,and then a pyrene polyporous organic polymer(Py-POP)was prepared by Suzuki coupling reaction with 1,4-benzodiboric acid.Then mixed with DVSBCB and pre polymerized to obtain a cyan green emitting Py-POP/pre-p-DVSBCB resin,which encapsulates a 365 nm ultraviolet LED chip.Finally,PBI-POP/pre-p-DVSBCB resin and Py-POP/pre-p-DVSBCB resin were mixed in a certain proportion to form(PBI/Py)-POP/pre-p-DVSBCB resin,which was used to encapsulate 365 nm ultraviolet LED chips.The experimental results indicate that the maximum emission wavelengths of TBr-Py and Py-POP are 414 nm and 452 nm,respectively.In addition,there is an aggregation induced quenching(ACQ)phenomenon in the fluorescence emission of Py-POP in mesitylene.In this experiment,when the mass of Py-POP added is 10 mg,the intensity of UV absorption and fluorescence emission is the highest.Py-POP/pre-p-DVSBCB resin was used to package 365 nm ultraviolet LED chips,and a turquoise green LED light source with a main wavelength of 495 nm,chromatic coordinates of(x=0.22,y=0.36),and an optical efficiency of 9.5 lm/W was prepared.Encapsulating a 365 nm ultraviolet LED chip with(PBI/Py)-POP/pre-p-DVSBCB resin(1:8)can obtain a warm white LED light source with a main wavelength of 557 nm,chromatic coordinates of(x=0.33,y=0.40),optical efficiency of 2.1 lm/W,and color temperature of5338 K.