Faraday Cage for EMC Improvement of Electronic Devices

摘要

In conventional packaging there is a considerable scope of noise coupling with external environment. This may cause the device in concern to fail due to EMI and may also cause other electronic device in the vicinity to fail due the electro-magnetic radiations from the device in concern. In order to reduce the coupling between two high frequency signals, providing a ground shield between them is a common practice - both inside the die as well as on the BGA packages. In Lead frame packages, the technique is though limited to extremely small pin packages (6 - 10 pins) wherein a portion of the flag metal is cut in such a way so as to provide a ground shield between the pins. This technique fails for medium or high pin packages. The only other option is to connect every alternate lead to ground to reduce coupling noise between the package pins. This reduces the effective number of usable pins and is not desirable. Resultantly, the lead frame packages suffer from low noise immunity for highly sensitive signals, leading to functional failures.