FCBGA Comes Into PCB Microelectronics Assembly

OEMs and in particular medical equipment OEMs should become familiar with a packaging term now being introduced into PCB microelectronics assembly. This packaging involves a combination of flip-chip and BGA (FCBGA) packaging, Fig. 1.

Figure 1: A BGA and a flip-chip interposer. (Source: Thorsten Meyer, Wikipedia, with minor modifications in red)

FCBGA is critical due to the demand for smaller circuitry, packaging, and ever-shrinking PCB real estate. Newer, smaller, portable, implantable, and ingestible medical devices will soon be relying on FCBGA packaging.

Check out our SMT007 column to get more details. In the meantime, here are some tips and hints to provide you a better understanding of FCBGA.

• FCBGA is a critical factor in the PCB microelectronics assembly and manufacturing of newer, smaller medical, mil/aero, commercial, and industrial devices.
• Flip-chip shrinks conventional BGA down to one-third to one-fourth the original size. All necessary connections fit into that size.
• OEM and EMS provider must understand the new advances in the redistribution of layers (RDL).
• Both OEM and EMS provider must collaborate on the correct flip-chip material, whether it’s organic or inorganic for making the substrate.
• Decision on whether to use C4 or C2 material for flip-chip bumps.
• Discussions and recommendations relating to wafer size, whether it’s six-, eight-, or 12-inch.

Introduction of FCBGA presents new questions and challenges for PCB microelectronics assembly. They are best resolved when OEMs get an early start with their EMS providers to discuss how to effectively approach the microelectronics assembly of new and smaller devices, whether they be of medical, military, industrial, or commercial in nature.

The important thing to keep in mind is that you are creating a flip-chip from a BGA and still making the same connections. The result is utilizing only 30–40% of the circuit board space to perform all the connections and make an equally functioning device.