What are the packaging methods for LED light sources for lighting?

Also known as the traditional LED package, it is often used in the package structure of 3-5mm LED. The disadvantage is that the package has a large thermal resistance (greater than 100K/W), a small current (20-30mA), and a low power (less than 0.1W). The life is short, and the brightness is not high. Most of them are the package of indicator type LEDs, which are mainly used for display or indicating illumination of instruments, and can also be used as a display source for large-scale integration.

The second is a SMT-LED package.

It is a packaging technology that directly attaches or solders a packaged device to a specified location on a printed circuit board (PCB) surface by pre-coating the chip pins with a specific tool or device. The solder and paste paste pattern is then directly pasted onto the printed circuit board PCB surface of the un-drilled mounting hole. After wave soldering or reflow soldering, a reliable mechanical and electrical connection between the device and the circuit is established. The plastic leaded chip carrier (PLCC) is used as the outer casing and has a large viewing angle.

It is characterized by better resolution of brightness, flatness, consistency and reliability. The product is light and thin, suitable for automated mass production, so it is the most popular packaging technology and process in the electronics industry.

The third is power LED package

This kind of package is to obtain a high and stable luminous flux. To improve the luminous flux of the LED, new technologies such as effective heat dissipation and non-degraded packaging materials must be used to solve the problem of LED light decay. The package and packaging process become the most critical technology. One of the thermal characteristics of power LEDs directly affects the operating temperature, luminous efficiency, wavelength of illumination, and lifetime of the LED.

Therefore, the advantage of the power LED is that the heat dissipation is good, only 14 ° C / W, only one tenth of the conventional package LED, the thermal characteristics of the power LED directly affect the LED operating temperature, luminous efficiency, luminous wavelength, service life, etc. And other parameters. The famous single-chip W-class power LED was first introduced by Lumileds in 1998 as the "Luxeon LED" chip.

The fourth is multi-chip integrated package (COB )

It is a kind of packaging technology that directly bonds the LED chip to the printed circuit board (PCB) through adhesive or solder, and then electrically interconnects the chip and the printed circuit board (PCB) through wire bonding. The COB technology is mainly used. Compared with the chip-mount (SMT), the LED package of the high-power multi-chip array not only greatly increases the density of the package power, but also reduces the package thermal resistance (6-12W/mK), and can appropriately add red light. Improve color rendering.

COB LED products have the advantages of uniform light output, no color spots, small glare, fast heat conduction, effective reduction of light decay speed and long life. At the same time, they have stable performance, easy assembly, no straight insertion angle, and no additional printed circuit board. PCB) is the main packaging method for indoor LED products, and has been developed to the fourth generation MLCOB (increasing reflective cup).

In order to improve the packaging efficiency of LEDs, many new technologies related to packaging, such as laser lift-off (LLO) technology, Flip Chip technology, thin film chip technology or thin film flip chip (TFFC) packaging technology, have been developed. Package (CSP) technology. And the so-called LED "three no" technology (no package, no heat, no power), and even "four no" technology is to improve the luminous efficiency of LED.