Membrane switch is the flexible insulating materials (PET) and conductive layer (silver paste, carbon powder) a multilayer structure consisting of planar non-locking key switch.It includes a conductive graphics (contact switch) the elasticity of the insulation film and keep a schedule of isolation layer element, can be caused by one or a combination of more than one switch contact.For membrane switch finished product should from what respect to test whether qualified?
The first requirement about shape: shape, conductor lines, insulation treatment, combination of lining board, and other should comply with the regulations of drawings or provide samples.
The second request about the material: substrate, silver paste, carbon ink, spacers, adhesives, glue, reinforcement plate, insulation printing should comply with the regulations of the drawings.
Asked about the combined state 3: chip surface must not have residual materials, foreign bodies, stain, concave and convex and attached to the surface and the fats, fingerprints, punch the appearance of burr on line.
The fourth requirement about foreign bodies: line can not have any foreign body attached on it.
Fifth asked about scars: all lines and contact shall not be cut through table (that is, the cut on the line cut to base material).Minor scratches and does not affect the impedance for the principle.Carbon ink surface scratch have an extremely easily, the scratch will not affect the circuit conduction as the criterion.