A kind of LED filament and manufacturing method thereof

Abstract

The invention provides an LED (Light Emitting Diode) lamp filament and a manufacturing method thereof. An LED chip is encapsulated on the edge top surface of a thin and long sheet metal support of the LED filament innovatively, meanwhile the sheet metal is inserted into a preformed transparent plastic model frame to produce a light source, and accordingly the automated continuous production of the LED lamp filament is implemented and the problem of the facing direction strength caused by the too thin and too long metal support is solved due to the transparent plastic model frame; meanwhile the lateral direction strength of the metal support is effectively utilized and accordingly the integral mechanical strength of the LED lamp filament is ensured; the heat dissipation characteristics of the metal is directly utilized, meanwhile the heat dissipation efficiency of the LED chip is maximized through the innovative encapsulation of thermal conductive coatings, and accordingly the problem of a heat dissipation bottleneck of the LED lamp filament is effectively solved, the LED lamp filament can work at the rated power for a long time, and the cost is reduced; the LED light extraction efficiency is improved, the light attenuation is reduced, the high lighting effect and ambient light of lamp filament light emission is implemented, and the market vacancy of the existing LED lamp filament is filled through innovative fluorescence encapsulation materials.

Description

technical field [0001] The invention relates to the technical field of LED lighting, in particular to an LED filament with high reliability and high luminous efficiency and full-circumference light and a manufacturing method thereof. Background technique [0002] At present, LED light sources have been widely used as a new type of lighting device, and LED lighting devices with various structures have appeared, including LED bulbs, LED three-dimensional light sources, LED light strips, and LED filaments. With the expansion of the need for outdoor display lighting and decorative effect lighting, LED filaments are widely used. The existing LED filaments mainly use a structure in which silica gel is fully covered with a strip bracket and LED chips are packaged on the strip bracket. Most of the brackets use sapphire, ceramics and glass. The existing filament structure has the following defects: 1) The thermal reliability of LED is poor. At the current stage of packaging technolog...

AI Technical Summary

Problems solved by technology

With the expansion of the need for outdoor display lighting and decorative effect lighting, LED filaments are widely used. The existing LED filaments mainly use a structure in which silica gel is fully covered with a strip bracket and LED chips are packaged on the strip bracket. Most of the brackets use sapphire, ceramics and glass. The existing filament structure has the following defects: 1) The thermal reliability of LED is poor. At the current stage of packaging technology development, the biggest problem affecting LED performance is actually the reliability of heat dissipation. , this kind of filament is sealed with full silica gel, and the thermal conductivity of silica gel is very poor (it can be regarded as insulation material), and it is impossible to avoid heat generation when all LED chips emit light, because of the material The thermal conductivity is very poor, and the heat generated by the chip will accumulate inside the silica gel layer, resulting in high temperature, which will destroy the molecular structure of the silica gel and cause the LED to fail

2), the mechanical strength is too low, resulting in low reliability

Because the current products of this type are all slender strips (generally less than 2mm in diameter and more than 30mm in length), and the bracket materials used are all materials with poor mechanical properties, such as glass, ceramics, and sapphire. In terms of external force, there is basically no elastic deformation, so during the assembly process of lighting application products, such filaments are easily damaged due to the clamping force that must be applied during the assembly process

3) The production efficiency is low. The LED filaments on the market are all packaged on a bracket with a width of about 1mm. Because the mechanical strength of the bracket is very poor, the possibility of automatic sealing is almost zero, and all rely on high precision. The dispensing machine dispenses single glue, and the requirements for the amount of glue dispensed are particularly strict. A little more glue flow will lead to defects, a little less will cause the chip to emit light, and a little touch will directly lead to failure. The existing filament structure Impossible to automate production

4) The cost of materials is high. Due to the thermal conductivity of the packaging material itself, it is impossible to use the rated power of the LED chip for the current LED filaments on the market. They are used at least half of the power, so that they can be used after packaging. The working life of the LED filament is more than 100 hours. To make the working life of the LED filament longer, the actual power of the LED must be greatly reduced. In this way, the number of LED chips used for the same power will increase, resulting in high costs.

5) The light attenuation is too large, and the current LED filament is difficult to achieve full-circle light emission, and it is impossible to use the rated power of the LED chip to work due to the defect of thermal conductivity, resulting in poor overall luminous efficiency of the LED filament and too large light attenuation , which seriously reduces the service life of the LED filament

In order to overcome the defects of the above-mentioned sapphire, ceramic and glass brackets, metal brackets are also used in existing LED lighting devices, and the high strength and good thermal conductivity of metal brackets are used to improve the performance of LED light sources, but the existing LED lighting devices using metal brackets are all The LED chip is packaged on the surface of the metal bracket, and the light source formed is an LED surface light source. Even if the surface of the metal bracket is narrow, it is also an LED strip, which cannot be used as an LED filament. Therefore, there is no such thing in the prior art. There is no LED filament lighting device with high reliability and high light efficiency and full-circumference light, which is a technical gap in the market

Images