Do you know why metal domes don't pop up when pressed?
The metal dome cannot bounce back when pressed, which is also called the metal dome dead key phenomenon. This is fatal to the metal dome and directly causes the entire product not to work properly. So why does the metal dome have a dead key phenomenon? Let's simplify it below. Analyze it.
The reasons why the metal dome does not rebound may be as follows:
1. The thickness of a conventional metal dome is 0.06mm, and its life span is 500,000-1.5 million times (according to load requirements). When the life span reaches or exceeds 2 times the design life, it is easy to cause the KEY to die without rebound;
2. The conventional design rebound value of the metal dome is ≧40gf. When it is lower than the special design value of 40gf, as the service life is extended and reaches the life limit, the KEY will not rebound and die;
3. The metal dome is made of stainless steel, and its designed thickness is generally in the [0.06~0.1mm] range. The conventional design load value is 100~300gf. When the metal dome bears more than twice the design load for a long time, it is easy to cause No rebound;
4. When the release film of the metal dome patch is torn off before attaching to the PCB board, or when the metal dome patch is produced and the operation is bent, the metal dome will bend due to external force and will easily fail to return. KEY bounce phenomenon (the metal dome is damaged or creased, or the concave structure of the metal dome itself is changed due to external force);
5. The metal dome patch is not designed with ventilation slots. When the metal dome travels, the air cannot be discharged, causing the load to be unable to press and form a dead key phenomenon;
6. When the design does not reserve a pre-pressure stroke, the silicone or plastic guide posts will act on the dome for a long time, causing the metal dome to become heavy, reducing the service life of the metal dome, and causing a dead key or non-pressing function.