What are the production processes of led lamps?

I. Production technology

A) cleaning: cleaning PCB or LED bracket with ultrasonic wave and drying.

B) Mounting: after the bottom electrode of the LED die (wafer) is prepared with silver glue, it is expanded, and the expanded die (wafer) is placed on the crystal thorn table. Under the microscope, the die is mounted on the corresponding pads of PCB or LED bracket one by one with a crystal thorn pen, and then the silver glue is sintered and solidified.

C) pressure welding: connect the electrode to the LED die with aluminum wire or gold wire welder as the lead wire for current injection. When LED is directly mounted on PCB, aluminum wire welder is generally used. (Gold wire welder is needed to make white top LED)

D) packaging: epoxy resin is used to protect the LED die and bonding wire through dispensing. Dispensing glue on PCB has strict requirements on the shape of cured glue, which is directly related to the brightness of finished backlight. The process will also undertake the task of lighting phosphor (white LED).

E) Welding: If the backlight is a D-LED or other packaged LED, the LED needs to be welded to the PCB before the assembly process.

F) Film cutting: various diffusion films and reflective films required by backlight are cut by a punching machine.

G) Assembly: According to the requirements of drawings, manually install various materials of backlight in the correct position.

H) Testing: Check whether the photoelectric parameters and light uniformity of the backlight are good.

I) Packaging: the finished products are packaged and put into storage as required.

Second, the packaging process.

1.The task of LED packaging.

The external leads are connected to the electrodes of the LED chip, which protects the LED chip and improves the light extraction efficiency. The key processes are assembly, pressure welding and packaging.

2.LED package form.

LED packaging forms can be said to be various, mainly according to different applications, adopting corresponding external dimensions, heat dissipation measures and luminous effects. According to the different packaging forms, LEDs can be divided into light LEDs, top LEDs, side LEDs, D LEDs, high-power LEDs and so on.

3.LED packaging process.

Three. Description of packaging process

1. Chip detection

Microscopic examination: whether there is mechanical damage on the surface of the material, whether the chip size and electrode size of Lockhill meet the process requirements, and whether the electrode pattern is complete.

Unfold film

Because the LED chips are still closely arranged after dicing, the spacing is very small (about 0. 1mm), which is not conducive to the later process work. We use a film stretcher to expand the film of bonded chips, so as to stretch the spacing between LED chips to about 0.6 mm. Manual expansion is also possible, but it is easy to cause bad problems such as waste of chips.

Distribute glue

Apply silver glue or insulating glue to the corresponding position of LED bracket. (For GaAs and SiC conductive substrates, red, yellow and yellow-green chips with back electrodes are made of silver paste. For blue and green LED chips with sapphire insulating substrate, insulating glue is used to fix the chips. ) The process difficulty lies in the control of dispensing amount, and the height and dispensing position of colloid have detailed process requirements. Because there are strict requirements for the storage and use of silver glue and insulating glue, the proofing, stirring and use time of silver glue are all matters that must be paid attention to in the process.

Prepare glue

Contrary to dispensing, glue making is to apply silver glue to the electrode on the back of LED with a glue making machine, and then install the LED coated with silver glue on the LED bracket. The efficiency of dispensing is much higher than dispensing, but not all products are suitable for dispensing.