What is Chip on Board？
Chip on Board (COB) is a semiconductor assembly technique where bare chips are directly mounted onto printed circuit boards (PCBs) and interconnected with fine wire bonds. The assembly is then encapsulated in epoxy resin, which protects the chips and wires from physical and environmental damage.
The Manufacturing Process of Chip on Board
The manufacturing process of COB technology is intricate and requires precision. Here’s a step-by-step guide:
- Die Attachment: The semiconductor dies are attached to the PCB using a conductive or non-conductive adhesive.
- Wire Bonding: Ultra-thin wires connect the die to the PCB, ensuring electrical connectivity.
- Encapsulation: The dies and wires are then encapsulated in a blob of epoxy resin, which is cured to form a solid protective layer.
Advantages and Disadvantages of Chip on Board
Advantages：
Better Performance: It makes the operation faster by reducing the distance between the components, which reduces signal loss.
Smaller and Cheaper: By getting rid of the need for traditional packaging of chips, it reduces the cost of manufacturing.
Disadvantages：
Physical Damage Risk: If not properly encapsulated, the exposed chips on the PCB can get damaged by physical impacts and environmental factors.
Repair and Maintenance Challenges: Because of the encapsulation and the compactness of the assembly, repairs can be more difficult compared to traditional PCBs.
Comparison of COB with Traditional PCB Technologies
| Feature | COB | Traditional PCB |
| Size | Smaller footprint | Larger footprint |
| Cost | Lower | Higher |
| Performance | Enhanced efficiency | Standard efficiency |
| Assembly Process | Simplified | Complex |
COB technology is a big step forward in how we put chips together. It makes things faster, smaller, and cheaper. But it also makes them more fragile and harder to fix. As technology keeps moving forward, we will have to decide how much we want to use COB and how much we want to stick with the old ways.
