Assembly and Packaging - BGA Substrates - Chip Scale Packaging

Flip-chip technology is so called because the package assembly is accomplished by inverting, or "flipping" the IC die to make connection with the substrate directly. Unlike conventional interconnection using wire bonding, I/O and power connections are made with solder or gold bumps. The bonding pads can be distributed over the surface of the chip, not just along the periphery. Therefore the chip size can be reduced and the circuit path can be optimized, and the absence of bonding wires eliminates wire inductance. For these reasons, flip-chip technology is widely used for chips with very high I/O counts and speed specifications.

Some features and advantages of flip-chip technology include:

• High density interconnect --- Allows far higher I/O counts than conventional packaging
• Low overall cost --- Allows smaller die sizes than conventional packaging
• High thermal performance --- Allows heatsink to be mounted directly to the die backside
• High speed performance --- Connection routes and induction can be minimized
• Small component size --- Array layout and elimination of wire and mold height