Electromagnetic interference signals are annoying and even troublesome for our electronic devices. To understand it in simple words, electromagnetic interference or EMI is the disturbance which hinders the operation of electronic devices. When dealing with radio frequency, it is addressed as radio-frequency interference or RFI. These interferences cause disturbances which can degrade and limit the effectiveness of a circuit within the device.
The EMI/RFI interference is of two types, Narrowband and Broadband. Both these interferences affect the electrical circuit and industries are required to protect their equipment from these disturbances. For this reason, EMI/RFI shielding is used to limit the electromagnetic field in an area by blocking the fields with barriers.
In this process, a magnetic or conductive material is used as a barrier to cover the casings of electrical devices in order to limit disturbances from the outside environment. The shielding agents are normally acrylic based sprays which are either painted or brushed-on coatings of electronic housings. These shields contain extremely pure metals such as copper, silver, and nickel, to help eliminate the EMI/RFI interference.
In the present electronic age, it is become essential to protect our electronic devices from EMI/RFI. However, it is equally important to make sure that your equipment isn’t doing any of the interfering. It is necessary to properly manage the RFI and EMI shielding to ensure their functionality. To make sure that the shielding remains functional for a long time, here we have listed some useful tips for you.
Tips for proper EMI/RFI shielding
- One of the major concerns is eliminating the heat from components inside of the EMI or RFI lids and covers. To solve the heat issue inside the shielding cans, ventilation holes along the top surfaces are useful. Moreover, to ensure proper thermal management, high power chips can be attached to the EMI/RFI cover before attaching the lid/cover to the circuit board. For best results, heat the lids to above 60 degrees Celsius before attachment.
- Shielding effectiveness depends on various factors. The purpose of shielding is creating a conductive layer completely surrounding the object you want to shield. People are often worried about fixing an EMI/RFI shielding leakage. To solve the issue of an EMI/RFI shielding leakage, treat it with a conductive caulk.
- Most of the latest electronic equipment may need EMI gaskets to help avoid the radiation of frequency waves interfering with other electronic sources. In the case of RFI shielding, the problem of ineffective gaskets is often due to faulty installation. However, it is essential that the RF gasket is placed properly and the surface of the gasket must be conductive, rigid and recessed. There is a growing concern regarding shielding gaskets is about the most cost-effective methods for covers of electrical devices. The most cost-effective method, in terms of material, is form-in-place gasket placing, although this is comparatively costly in terms of manufacturing. In place of form-in-place EM/RFI shielding gasket, pre-form shaped-gaskets, with a conductive pressure sensitive adhesives as a high volume can be used.
- Typically, the shielding layer will be made up of conductive sheets or layers of metal. For those who want to have a see-through window in their design, a blackened mesh can be used.
With the increasing complexity of electronic devices/systems, the issue of electromagnetic interference has risen. EMI or RFI are emitted by the various source or are radiated through openings of any kind. Therefore, protecting, as well as, preventing electronics from causing interference has become very important. As such, various products like EMI shielding gaskets, conductive tapes, and more are used in various industries, such as military, aerospace, medical, fluid sealing, environmental and microwave applications.