Introduction of COB light source

- Sep 12, 2018 -

Introduction to COB light source and what are its advantages and disadvantages.


COB integrated light source (ChipOnBoard), that is, the bare chip is adhered to the interconnect substrate with conductive or non-conductive glue, and then wire bonding is performed to realize electrical connection. The COB integrated light source is also called a COB planar light source.

The COB integrated light source is covered with a thermally conductive epoxy resin (usually an epoxy resin doped with silver particles) on the surface of the substrate, and the silicon wafer is directly placed on the surface of the substrate, and heat treated until the silicon wafer is firmly fixed on the substrate. Wire bonding is used to establish an electrical connection directly between the silicon wafer and the substrate. 

There are two main types of bare chip technology: one is COB technology and the other is flip chip technology (FlipChip). Chip-on-board (COB), semiconductor chip is placed on the printed circuit board, and the electrical connection between the chip and the substrate is achieved by wire stitching. The electrical connection between the chip and the substrate is achieved by wire stitching and covered with resin to ensure reliability. . Although the COB integrated light source package is the simplest bare chip placement technology, its packaging density is far less than that of TAB and flip chip bonding.


Its main features are as follows:


     1, can be freely combined and combined to form a variety of LED lamps, easy to assemble. It can overcome the shortcomings of large size and high cost of the patch LED.


     2, high reliability, no dead lights, no plaque. Its precision packaging process allows the chip to be fully dissipated to ensure the quality of the chip and extend its life.


     3, even light, soft light, no glare, does not hurt the eyes. Being able to directly overcome the market is LED high-power dazzling. Shortcomings.


     4. High color rendering index and high light efficiency. It can achieve 120lm/w and the illumination angle is above 120°. Cost savings, no need to do another PCB board, green and environmentally friendly, no pollution.


     5. Under normal current, the attenuation is minimum, and the control is less than 3% within 1000H.


     6, safe and reliable, all work below 50V, fully considered for the application of certification.


     COB integrated light source has so many advantages, it has also been widely used in LED lighting, LED downlights, LED spotlights, LED ceiling lights and so on. It is one of the mainstream of LED lighting sources.