

FLIP CHIP and UNDERFILL
Flip Chip (C4), also known as controlled collapse chip connection, is a method of interconnecting IC chips with solder balls/ bumps that have been deposited onto the top side IC chip bond pads to a substrate. The IC chip is flipped over during assembly so that its top side faces down. Solder balls/ bumps are eutectic (Sn63Pb37) or lead free (SAC305).
Flip Chip (TCB) also known as thermo-compression bonding, is a method of interconnecting IC chips with fine pitch copper pillar. It is often recommended for high frequency applications with compact dimensions ≤100um pitch, enabling higher I/O counts, short interconnection paths and small form factor.
Underfill is applied to the stand-off distance between the die and substrate with a non-conductive adhesive after the die is connected. The underfill provides stress relief between the die and substrate, provides robustness, and protects the component from any moisture.
Flip Chip Capabilities
- X/Y placement +/-3um accuracy, theta placement +/-0.15° accuracy.
- Flip Chip (C4): 150um to 300um pitch with solder balls/ bumps.
- Flip Chip (TCB): 30um to 100um pitch with copper pillar.
- Flip Chip Ball/ Bump: Sn63Pb37 or SAC305 solder balls/ bumps.
- Flip Chip size: 500um to 25,000um (0.020” to 1.00”).
- Flip Chip thickness: 150um to 500um (0.006” to 0.020”).
- Flip Chip pick from: 2”x2” and 4”x4” waffle pack, and JEDEC tray.
- Flip Chip place to: Rigid & Flex PCB laminates and ceramic substrates.
- Underfill to provide stress relief, robustness and protect from moisture.
- Microfocus 160Kv XRAY inspection with void analysis.
- Metrology for precision measurement of substrate and assembly.