With the development of smart phone, the mechanical key has been already eliminated from the stage. There is only the HOME key left on the front side of the phone. Even sometimes the HOME key is also out and there are only two keys left–volume key and power key. These two are usually used a FPC to save cost as well as space. The structure showing as below:
For the design of volume key and power key, there are two things required to considerate. On one hand, the position of the flex circuit. Since the flexible circuit is glued on the supported wall, three directions need to be limited if you would like to fix the FPC. As well, the designers still need to consider the installation position of the keys itself, which determines the basic structure of the keys.
On the other hand, the volume key and power key are moving parts. Therefore, taking the stroke of metal domes into account is necessary and as general rule the stroke is 0.3. In addition to hard contact mode, there is also a soft contact mode (P+R), which is to use rubber or TPU (Thermoplastic polyurethanes) for the part where the key is contact with the dome, so that the sound is softer.
Best Technology is the premier expert in the manufacture of electronic components, brings a unique combination of technology and quality that offers a competitive supply of flex circuits and rigid-flex circuits and other flexible circuit products. To find out more, contact Best Technology at 0755-29091601 or check the website: https://www.bestfpc.com/