Preparation method of silver colloid for LED (Light Emitting Diode) with high thermal conductivity

Abstract

The invention relates to a preparation method of a silver colloid for an LED (Light Emitting Diode) with high thermal conductivity. The method comprises the following steps of: ball-milling and activating carbon nano tubes; after carrying out ultrasonic dispersion in organic solution, mixing and stirring with the silver colloid to obtain mixed liquor of the carbon nano tubes and the silver colloid; putting the mixed liquor into a flat magnetic field with the magnetic field intensity being 10-25 Tesla, or a high frequency alternating electric field with the electric field intensity being 1-2.5*10<6>V / m and the frequency being 1-10MHz; and after directional aligning the carbon nano tubes, heating the mixed liquor, so that the organic solution is volatilized, and the viscosity is improved. The electric field and the magnetic field are simultaneously adopted to directionally align the carbon nano tubes in the mixed liquor, so that the heat-conducting property of the silver colloid can be well improved. Through selection of the intensity and the direction of the electric field and the magnetic field, the control on the orientation, the density and the distribution of the carbon nano tubes is realized; and silver colloid solution of the directionally aligned carbon nano tubes with different densities and distributions can be obtained, and is then used for packaging the LED.

Description

technical field [0001] The invention belongs to the technical field of processing silver glue for LEDs with high thermal conductivity, and in particular relates to a method for controlling the orientation, arrangement and distribution of carbon nanotubes. Background technique [0002] LED has the advantages of energy saving and environmental protection, long service life, small size, etc., and is widely used in display screens, traffic signal displays, automotive industry lamps, backlight sources, lighting sources and other fields. The conductive silver glue is an indispensable colloid in the production of LED packaging. The requirements for the conductive silver glue are electrical conductivity, good thermal conductivity, and strong adhesion. After years of development, with the development of the LED industry towards brightness and high power, newer and higher requirements have been put forward for the optical, thermal, electrical and mechanical structures of silver glue u...

AI Technical Summary

Problems solved by technology

[0008] The domestic patent (application number 201010155343.7) introduces that the carbon nanotube mixture is placed in a flat magnetic field, then baked and solidified at room temperature, and finally cut into pieces and printed with circuits. This method is complicated to operate and difficult to process.

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