Brief description of LED production process and LED packaging process

First, LED production process

1. Process:

a) Cleaning: Ultrasonic cleaning of the PCB or LED holder and drying.

b) Mounting: After the silver electrode is placed on the bottom electrode of the LED die (large wafer), the expansion is performed, and the expanded die (large wafer) is placed on the thorn crystal table, and the die is punched under the microscope with a stylus. One by one is mounted on the corresponding pad of the PCB or LED holder, and then sintered to cure the silver paste.

c) Pressure welding: Use an aluminum wire or gold wire welder to connect the electrodes to the LED dies for current injection. The LED is directly mounted on the PCB, and an aluminum wire welder is generally used. (Making a white light TOP-LED requires a gold wire welder)

d) Packaging: The LED die and bonding wires are protected with epoxy by dispensing. Dispensing on the PCB, there are strict requirements on the shape of the gel after curing, which is directly related to the brightness of the backlight product. This process will also take on the task of a point phosphor (white LED).

e) Soldering: If the backlight is an SMD-LED or other packaged LED, the LED needs to be soldered to the PCB before the assembly process.

f) Film cutting: Various diffusion films, reflective films, etc. required for backlighting by a punch.

g) Assembly: Manually install the various materials of the backlight in the correct position according to the drawings.

h) Test: Check whether the backlight photoelectric parameters and uniformity of light output are good.

I) Packaging: The finished product is packaged and put into storage as required.

Second, the packaging process

1. The task of LED packaging

It is connected to the outer lead electrodes of the LED chip, while protecting the LED chip and acts to improve the light extraction efficiency. The key processes are mounting, pressure welding and packaging.

2. LED package form

LED package form can be said to be varied, mainly according to different applications, the corresponding size, heat dissipation measures and light-emitting effects. LEDs are classified into Lamp-LED, TOP-LED, Side-LED, SMD-LED, High-Power-LED, etc. in package form.

3. LED packaging process flow

Three: packaging process description

Chip inspection

Microscopic examination: whether there is mechanical damage on the surface of the material and the pithill

Whether the chip size and electrode size meet the process requirements; whether the electrode pattern is complete

2. Expansion

Since the LED chip is still arranged with a small close spacing (about 0.1 mm) after dicing, it is not conducive to the operation of the post process. We use a film expander to expand the film of the bonded chip, and the distance between the LED chips is stretched to about 0.6 mm. It can also be manually expanded, but it is easy to cause problems such as chip falling waste.