Embedded Decoupling Capacitance (EDC) I
NCMS Project #: 160213
Problem: The need for power-ground decoupling capacitance is nearly universal in electronic circuits. Today, this need is satisfied through discrete chip capacitors. However, as circuit designs increase in speed, the effective use of decoupling capacitors is becoming more difficult to achieve. The parasitic inductance associated with the circuit connections of the decoupling capacitors decreases their effectiveness at higher frequencies. Decoupling capacitors also require valuable amounts of printed wiring board surface area, consuming up to 50% of the total board area. The increasing packaging densities are creating a desire to free up valuable surface real estate currently occupied by discrete capacitors.
Benefit: This project demonstrated that embedded capacitance technology is an effective alternative to the use of discrete decoupling capacitors for power supply decoupling. Many benefits to design and assembly activities will be realized as this technology evolves.
Solution/Approach: The goal of the EDC Project was to evaluate the performance of distributive embedded capacitance in circuit boards for power supply decoupling and electromagnetic interference (EMI) suppression and to compare the results with standard surface mount technology (SMT). To achieve this goal, it was necessary to demonstrate that available EDC materials are manufacturable, that they have the physical properties to electrically perform as discrete capacitors do, and that printed wiring boards (PWBs) containing them are reliable.
It was also important to understand power supply decoupling, and to develop the ability to predict how and when embedded capacitance will work for a given circuit design. The project took some of the first steps towards the realization of embedded passives in organic substrates.
DoD Participation:
- U.S. Army (Tobyhanna Army Depot)
- National Institute of Standards and Technology (NIST)
Industry Participation:
- Raytheon Systems Company
- Litton Interconnect Technologies
- Pennsylvania State University (Penn State)
- University of Missouri-Rolla (UMR)
- Merix
- StorageTek
- Delphi Automotive Systems
- Raytheon Systems Company
- 3M
- DuPont
- Polyclad Laminates, Inc.
- AlliedSignal
- HADCO
- NCMS