Thermal compression bonding (TCB) process is a key technology in advanced packaging, which can integrate high-density components such as 3D stacked chips and high bandwidth memory (HBM). TCB utilizes heat and pressure to bond materials, ensuring reliable electrical connections while maintaining the integrity of the semiconductor structures involved.
Its main process:
After coating, the substrate is adsorbed and fixed onto the heating plate.
2. Attach the chip to the head and suck it up, with the chip being vacuum absorbed.
3. Visual positioning: Move the position of the heat dissipation plate where the substrate is located slightly to align with the chip.
4. The BondHead moves downwards until it comes into contact with the substrate and stops.
5. Bondhead applies appropriate pressure while the chip is rapidly heated until the solder ball melts.
6. When the solder ball melts, BondHead continues to move the chip down a small distance to ensure that all bumps can be connected.
7. Keep the chip at this height for a certain period of time to ensure that the solder balls completely melt and infiltrate the connection points between the chip and the substrate.
8. Raise the BondHead to a certain height to achieve the expected welding height.

9.Finally, the BondHead rapidly cools down, the soldering becomes solid, the BondHead releases the vacuum, and returns to the standby position.
Throughout the entire process, TCB will monitor the temperature, bond force, and Z-direction displacement of the Bond Head in real-time, as shown in the figure. The entire welding process should not exceed 4 seconds.

Key technical points:
TCB operates by applying controlled temperature and pressure to two surfaces typically made of semiconductor materials. Heat softens the surface, allowing atoms to diffuse at the interface and promote bonding.
1. Thermal compensation technology for Z-position control: Heating the key head from 160 ℃ to 280 ℃ produces an increase of~15 μ m. Thermal compensation and servo control maintain the actual position.
2. Thermal stability and rapid cooling technology:
3. Process control technology: It is necessary to track the temperature, force, z-position, etc. of the bonding process for real-time monitoring.

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