FLIP CHIP and UNDERFILL
Flip Chip, also known as Direct Chip Attach (DCA), 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).
Once the die is connected, the stand-off distance between the die and substrate is typically filled with a non-conductive adhesive referred to as underfill. The underfill provides stress relief between the die and substrate, provides robustness, and protects the component from any moisture.
Flip Chip is often recommended for high frequency applications with compact dimensions, enabling higher I/O counts, short interconnection paths and smaller form factor.
Flip Chip Capabilities
- X/Y Placement +/-7um accuracy, Theta Placement +/-0.15° accuracy.
- Flip Chip Pitch: 0.15mm to 0.30mm with solder balls of 0.075mm to 0.15mm.
- Flip Chip Ball/ Bump: Sn63Pb37 or SAC305 solder balls.
- Flip Chip size: 0.50mm – 25mm (0.020” to 1.00”).
- Flip Chip thickness: 0.15mm – 0.50mm (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, Rigid-Flex PCB 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.
- Flip Chip assembly process: Pick & Flip, Pick & Flux, Align & Place, Reflow Solder, XRAY & Underfill.