US Patent 11404224 Keycap and key structure with same

A key structure is provided. The key structure includes a switch and a keycap. The switch includes a stem. The keycap is located over the switch. The keycap includes a pressing surface, an inner bottom surface and a protrusion post. The pressing surface and the inner bottom surface are opposed to each other. The protrusion post is protruded downwardly from the inner bottom surface. The protrusion post includes an insertion groove and at least one exhaust recess. When the stem is tightly fitted into the insertion groove, a gap is formed between the at least one exhaust recess and the stem.