How to strengthen grounding with FPC steel plate

The following methods are commonly used to realize steel plate grounding: 1. Bonding the steel plate with conductive adhesive or conductive adhesive film to ground; 2. Tinning and grounding the steel plate corner cutting point; Third, the middle of the steel plate is perforated and the silver paste is grounded. At the same time of the above method, FPC needs to open the window and expose copper at the positions of bonding, steel plate cutting and opening. Thank you!