What are the problems with LED chip packaging technology?

1. LED (Light Emitting Diode) packaging refers to the packaging of light-emitting chips, which is significantly different from integrated circuit packaging. The packaging of LED not only requires protection of the wick, but also transparency. So LED packaging has special requirements for packaging materials.
2. LED packaging technology is mostly developed and evolved based on discrete device packaging technology, but it has significant particularities. In general, the die of discrete devices is sealed inside a package, and the main function of the package is to protect the die and complete electrical interconnection. LED packaging is responsible for outputting electrical signals, protecting the normal operation of the chip, and outputting visible light. It has both electrical and optical parameters, and cannot simply package discrete components for LED design and technical requirements.

packaging process
The task of LED packaging is to connect the external leads to the electrodes of the LED chip, while protecting the LED chip and improving the efficiency of light extraction. The key processes include shelving, pressure welding, and packaging.
2. LED packaging forms can be said to be diverse, mainly adopting corresponding external dimensions, heat dissipation measures, and light output effects according to different application scenarios. Classified by packaging form, there are Lamp LED, ledTOP-LED, Side LED, SMD LED, High Power LED, etc.
3. LED packaging process flow
a) Chip inspection
Microscopic examination: whether there is mechanical damage and locking pits on the surface of the material, whether the chip size and electrode size meet the process requirements, and whether the electrode pattern is complete
b) Expansion piece
Due to the close arrangement and small spacing (about 0.1mm) of LED chips after slicing, it is not conducive to the operation of subsequent processes. We use an expansion machine to expand the film of the bonded chips, stretching the spacing of the LED chips to about 0.6mm. Manual expansion can also be used, but it can easily cause problems such as chip dropping and waste.