Test procedure for CoB (chip on board)

The production of CoB is basically the same as that of the IC sealing process. In addition to changing leadframe into a PCB and changing the sealing process from molding to dispensing, with triming & Marking missing, plating is missing, but plating is already included in the PCB coding process.

In addition, it also has a high requirement on the stability of the environment, because the recent cob programming also involves the evolution of the chip programming of IC, and the smaller it grows, therefore, any small fresh or other things may affect the reliability of the solder joints, and the contamination of gold may lead to a short circuit between the welding points.

This article will introduce the COB's manufacturing process and requirements for the non-chamber:

Process Flow Chart)

From this process, we can see that CoB will use PCB, die, silver glue, and Al wire) epoxy and other materials may have substitutes, but they cannot be replaced. Die attach will be used in programming) wire Bonding, dispenser, and oven.

It seems very simple, but it is also very simple, as long as you build a room without a room and enter the necessary machine to generate, however, to achieve a yield rate of more than 99%, it is necessary to maintain compliance and control of the entire process. Let's talk about it one by one later!

Cob environment requirements-No room

It is recommended that you have a clean room and a class under KB, generally, no room in the IC sealing industry is required to be at 10 K or even 1 K, and the crystal compaction industry is more advanced. Because Cob's processing process is similar to crystal seals, contamination of any small particles at the welding points will cause serious damage to the solder joints, how can we fix a house on the basis of rubbish.

There is also a need for basic clothes, hats, and anti-leech. It is not necessary to wrap your hair into a meat-style clothes, however, basic hats, clothes, and electric shoes are all necessary. The most important thing is to avoid being contaminated to the solder position when the wire bond occurs.

In addition, the locker room should be subject to the control box and any items that are easy to carry or produce dandruff. All packages should be split out of the photo room before they can be imported. This is to keep the photo room dry and prolong the life of the photo room.

Test procedure for CoB (chip on board)