Flip Chip

Flip chip (also known as direct chip attach) is the process whereby a semiconductor dies is attached bond pad side down to a substrate or carrier. The electrical connection is made using a conductive bump on the die bond pad.

Once the die is connected, the stand-off distance between the die and substrate is typically filled with a non-conductive adhesive called underfill. The underfill provides stress relief between the die and carrier, robustness and protects the component from moisture ingress.

• Typical Materials
  • Substrate: BT Laminate, Ceramic, FR4, silicon
  • Packages: Customer specified
  • Underfill: Hysol FP4530, FP4511, Fluxing Underfills etc.
  • Bump material; Au stud bumps, Eutectic, High Pb, Pb free, Sn coated Au ball bumps.
  • Die: Si, GaAs, GaN, SiGe, MEM’s, InP
• Attach Process
  • Thermosonic or Thermocompression Au-Au attach
  • Solder bump reflow processes
  • Epoxy-assisted processes on Au stud bumps

X-rays and cross-sections can be used to assess the interconnection joints, and temperature cycling used to assess the reliability.

Alter Technology UK’s expertise and capability in flip-chip bonding will reduce risk and reduce time to market for your flip-chip bonding requirements, as well as provide a cost-effective manufacturing option.