Bond pads located over circuitry could crack the traces routed underneath inner-die bond pads on the lower metal levels. However, from a practical standpoint, an area array of wirebonds would be unwieldy. This means that a minimal voltage gradient will exist across the die, nearly eliminating the effects of resistive drops and reducing inductive effects associated with peripheral power connections found with wirebond products. This greatly enhances the high-frequency characteristics of the package. Variations caused by wirebond wire tolerances are eliminated.
Variations caused by the solder ball are negligible when compared to the wirebond.
Another benefit is that the interface between the chip and the substrate does not vary. Besides improved electrical performance, flip-chip modules provide benefits in other areas. The thermal grease is more effective than an adhesive because it is typically thinner and void-free. Cross section of a flip-chip module depicting thermal enhancements. His career has spanned software engineering, analog and digital circuit design, and non-substrate packaging, including card and subassembly design in mainframes.