Sensitive electronic circuits need to be fully protected from extraneous electro–magnetic and radio frequency interference (EMI and RFI). This has typically been achieved by mounting metal shields or ‘cans’ directly to the PCB to fully shroud the required circuitry. These shields are often attached to the PCB using through–hole solder tails, manually soldered after the main assembly process. Not only is this time–consuming and costly but also, during initial setup and subsequent maintenance it is often necessary to access the circuitry and components under the shields. This requires de–soldering operations in often densely populated areas containing highly sensitive components. As a result there is a high risk of expensive damage occurring.
Harwin’s solution of using shield retaining clips, supplied in industry–standard Tape & Reel packaging, provide a automatic placement method which is soldered using standard SMT placement equipment. The shielding can is then fitted during final assembly within seconds. As it is possible to remove and refit the can a number of times, tuning and rework operations are simplified, and a minimal risk of damage is ensured. Therefore both initial production and rework costs are significantly reduced.
Harwin’s EMI/RFI clips are aimed at telecoms base stations, radio communications, data processing and in–car entertainment systems. Previous devices have been successfully used in diverse applications such as the Bowman Military radio project and automotive SatNav/DVD players.
See also EZ-Shield Cans