Thin film switch panel buttons are widely used in instruments, keyless switches are widely used in electronic circuits. Because it doesn’t have to go through a lot of electricity. As a result, it is usually small in shape and size and is often referred to as a touch key or a toggle switch. Mouse buttons and mobile phone keypads are typical examples of key switches without locks. Modern electronic equipment and instruments generally have the function of man-machine interaction. Touch key is the main part of human-computer interaction, including the system state of the key, the number of Keystrokes, the length of Keystrokes, and which keys are pressed to determine the appropriate response. With the development of man-machine interaction technology, the Membrane Keyboard Technology has replaced the light touch keyboard in many occasions. The membrane button can embed a plurality of metal contacts in the membrane panel which is composed of multi-layer membrane according to the user’s request. The metal connection is generated by printing and is connected to the external connection terminal by the FPC connection bar. Thin-film key touch small, you can achieve multi-key. At the same time, the mechanical design of the sheet is simplified. In addition, it also has a certain degree of waterproof performance, it is well received by the majority of users. However, because of the need to customize the film keys, the production process is complex, resulting in high costs. At the same time, the limit of its mechanical contact life and other factors, so that its application is also subject to certain restrictions.
There are many kinds of membrane switch, including planar switch, convex switch, flexible switch, rigid switch and so on. The manufacture of membrane switch has certain request to the panel, it is not only the decoration of the commodity appearance, but also plays the protective role, therefore in the manufacture of membrane switch, must satisfy the necessary condition, can make the membrane switch. The first appearance is good, the appearance should be flat, gloss universal. No mechanical operation, scratches, inclusions, stains and other external defects. Secondly, good weather resistance, in a certain natural environment, will not deformation, cracking, aging and discoloration. Panel layer has good chemical resistance, can be emergency different chemicals, but for most common chemicals, such as alcohol, ether, mineral oil should have a certain tolerance. In general, the key on the membrane switch can only use color to indicate the direction, shape and size of the main body. Therefore, the accuracy of the operation can only be recognized by the operator’s vision, because there is no appropriate response information to indicate whether the finger is acting in accordance with the useful scale of the switch, thus affecting the monitoring and operating speed of the whole machine. A switch makes the key body gently lift, slightly above the panel, to form a three-dimensional shape of the membrane switch, called the three-dimensional key switch.