SMD LED chip packaging process introduction
The specific operation of LED packaging
1. First is the LED chip inspection
Microscopic inspection: Whether there are mechanical damage and pitting on the surface of the material, whether the size and size of the LED chip electrode meets the process requirements; whether the electrode pattern is complete.
2. Expansion machine expands the film
Since the LED chips are still arranged tightly after dicing, the pitch is small, which is not conducive to the operation of the subsequent process. We use a film expander to expand the film of the bonded chip. The distance between the LED chips is stretched to about 0.6mm, and manual expansion can also be used, but it is easy to cause bad problems such as chip drop and waste.
3. Dispensing
Put silver glue or insulating glue on the corresponding position of the LED bracket. The difficulty of the process lies in the control of the amount of glue. There are detailed technological requirements for the height of the colloid and the position of the glue. Because silver glue and insulating glue have strict requirements on storage and use, the waking, mixing, and use time of silver glue are matters that must be paid attention to in the process.
4. Prepare glue
In contrast to the glue dispensing, the glue preparation is to use the glue preparation machine to first coat the silver glue on the back electrode of the LED, and then install the LED with the silver glue on the back of the LED bracket. The efficiency of glue preparation is much higher than that of glue dispensing, but not all products are suitable for the glue preparation process.
5. Manual splint
Place the expanded LED chip on the fixture of the stab table, put the LED bracket under the fixture, and puncture the LED chips one by one to the corresponding position with a needle under the microscope. Compared with automatic rack mounting, manual piercing film has an advantage, it is convenient to change different chips at any time, and it is suitable for products that need to install multiple chips.
