The hardware shield is a metal cover, its function is to shield the external electromagnetic wave’s influence on the internal circuit and the electromagnetic wave generated inside to radiate outward. Moreover, hardware shielding covers are widely used in walkie-talkies, connectors, mobile phones, computers, GPS, digital products, aviation and other fields. Shield manufacturers who have been focusing on the development and customization of shielding covers for 20 years summarize for everyone, shielding covers can be roughly used in the following 4 types of module positions: