Abstract: A method of making micro-holes on a metal plate includes: (A) feeding a metal plate on a workbench forward to extend beyond a shearing edge; (B) locating a punching head at a first position, and keeping a working space between the punching head and the workbench; (C) exerting a shearing force towards the workbench by the punching head; (D) bending the metal plate by the shearing force, and forming a plurality of spot-shaped cavities arranged in a row on a second surface; (E) bearing a shearing force on the first surface of the metal plate to form a linear groove; (F) deforming the metal plate by the shearing force to cause the spot-shaped cavities arranged in a row to communicate with the linear groove to form micro-holes; (G) the punching head returning to the first position and moving a working distance to a second position; (H) feeding the metal plate again; (I) the punching head repeating the above steps at the second position; (J) the punching head returning to the second position and then moving back to

Abstract: An electro-magnetic wave filtering and impeding board is made of metal and includes a first side and a second side. The first side has multiple linear slots and the second side includes multiple concaved geometric holes which communicate with the linear slots. The electro-magnetic waves are impeded by the metallic material and weakened when passing through the linear slots and the geometric holes so as to impede the electro-magnetic waves.

Abstract: A method of making micro-holes on a metal plate includes: (A) feeding a metal plate on a workbench forward to extend beyond a shearing edge; (B) locating a punching head at a first position, and keeping a working space between the punching head and the workbench; (C) exerting a shearing force towards the workbench by the punching head; (D) bending the metal plate by the shearing force, and forming a plurality of spot-shaped cavities arranged in a row on a second surface; (E) bearing a shearing force on the first surface of the metal plate to form a linear groove; (F) deforming the metal plate by the shearing force to cause the spot-shaped cavities arranged in a row to communicate with the linear groove to form micro-holes; (G) the punching head returning to the first position and moving a working distance to a second position; (H) feeding the metal plate again; (I) the punching head repeating the above steps at the second position; (J) the punching head returning to the second position and then moving back to