FPC thin-film key switch: the Microwave thin-film switch of the United States does not work how to fix, leakage is due to the microwave computer board by long-term moisture or water erosion caused, and from the appearance of the Circuit Board is sometimes difficult to determine whether leakage, so if necessary, you can directly use anhydrous alcohol wipe or clean film switch, FPC and computer board, mostly effective. This failure may also be caused by the FPC printed line at the same time several broken lines, but this is basically due to improper maintenance, it is relatively rare. Inspection as long as the naked eye or multimeter measurement, can quickly check the fault, re-welded broken line can, remove the fault. (2) failure of individual key switches on the keyboard. The main cause of the failure is the break line of FPC line or the bad contact of film switch. Can find the corresponding failure of the switch membrane switches, and lines, reference to the above method can be treated after troubleshooting.FPC thin film key switch: Thin Film Key introduction, thin film key is the “Key + film”basic structure, so, the key feel, characteristics and so on depend on the design of thin film key. Considering the reliability of switch contact separation and rebound, the thickness of thin film is 0. - 0.2 mm is the best, too thin springback is weak, contact separation is not sensitive. Thick reaction slow increase the strength of operation. Larger key body, such as the diagonal length of the square key or circular key diameter is greater than, choose 0.15 or 0.2 mm thick film. Thin film slightly thick, strong rebound, the key body after many times after the tendency of the film relaxation is smaller, so as to ensure the normal work contact. When the isolation layer thinner, the substrate film thickness should be thick, thin film easy to occur contact of the self-through. Planar buttons allow the selection of slightly thicker film material, and used for the circuit contact bubble film is Generally 0. MM thick film, only in the bubble ball diameter and the top of the string height of the smaller case, it is appropriate to use thicker film. The membrane button is the necessary structure in the electronic button products, it is the conductive film built in the metal spring sheet button products and the conductive adhesive button products, the function of the membrane button is to play the switch conductive role in the button products, commonly used in PCB and FPC Circuit Board conductive sheet. The structure of the membrane key is very simple. After the key cover and the key cap are taken off, the Membrane Circuit and the circuit board under the key can be seen.