Tracing to the source, we’ve been aware that COB (Chip On Board) is not a fresh technology. Although it has not been the mainstream tech in optical communication industry as before, and it still can not be ignored for the packaging of high-rate multimode 40G/100G optical transceiver module on account that it can help optical module to achieve smaller form factor and higher density. Maybe there are still some people confused of what advantages of COB tech are. Then in this post, Gigalight will introduce it for you.
What Is the COB (Chip On Board) Tech?
Chip On Board, or COB, is actually the chip technology mounted directly on a circuit board as opposed to being socketed. The core processes of COB model consist of DICE BOUND and WIRE BOUND. This kind of circuit board is also known as a “glop-top” for the blob of protective epoxy that protects and insulates the chip and its connections. All of the chip’s connections are hard-wired.
Advantages of COB (Chip On Board) Tech
Small in Size:
On account that IC chip is smaller than components with leading spacing, COB has outstanding advantages in space saving. dual-in-line package (DIP). The size of wire bonding chip without IC packaging is smaller than that of the dual-in-line packaging(DIP), covering about 1/4, saving more space than Leadless Chip Carrier(LCC)packaging, shrinking the size. COB tech can also be used in the application fields that other packagings have no way to achieve it.
Low in Cost:
COB tech is aimed to reduce costs and saving investments. Due to that uncovered IC chip is directly attached on the printed circuit board, wihout separate packaging for IC chip, so that the cost is reduced. And making the circuit interconnection line directly on the IC chip saves more costs than advanced packaging. Therefore, COB tech tends to be developed toward more improved IC chip.
With Mature Semiconductor Tech:
In the aspect of semiconductor tech, it is also developd toward COB tech. CMOS component with low power dissipcation is more suitable for COB tech with limited power. Simultaneously, with the IC chip developed toward the trend of consumption and semi-consumption, COB tech is more important.
With Good Sealing:
With the coefficient of thermal expansion between sealing materials and printed circuit board more and more matched, the reliability will be further improved. In the past, on account of the mismatching of coefficient of thermal expansion between sealant and printed circuit board, excessive strain are generated in the welding spot between the chip and printed circiut board. With the development of sealing materials, this issue is not very obvious. Therefore, COB tech is more attractive in more fields.
Feasible to Realize the Automation:
Many processes included in the COB tech can realize automatic production. After that, many manufacturers will be more interested in COB tech.
Above is an introduction to advantages of COB tech. Although it is with these advantages, and it also causes some problems, such as increasing the complexity of MPD monitoring of optics and so on, at the same time that it brings some coneveniences for manufacturers of optical components. Whether the challenges brought by COB tech will be overcome with the future advancement of tech, it remains to be seen.
Gigalight is a design innovator in global optical interconnect field. A series of optical interconnect products include: optical transceivers, passive optical components, active optical cables, GIGAC MTP/MPO cabling, cloud programmers & checkers, etc. Three applications are mainly covered: Data Center & Cloud Computing, MAN & Broadcast Video, and Mobile Network & 5G Optical Transmission. Gigalight takes advantage of its exclusive design to provide clients with one-stop optical network devices and cost-effective products.