By circuit, insulation panels, membrane switch isolation layer and the lower circuit four parts, for the light touch type is normally open to switch, so, let's together to learn about all aspects of the detection of membrane switch:
Break, short circuit, do not allow any conductor broken, short circuit phenomenon.
Foreign bodies: line should be attached to any foreign body.
The thickness of the conductor: general conductor thickness control in 7-12 microns, and should be even and smooth.
Top and bottom line position deviation: top and bottom line of the switch contact center position offset tolerance for Ф 0.5 mm..
Material: substrate, silver paste, carbon ink, spacers, adhesives, glue, reinforcement plate, insulation printing should comply with the regulations of the drawings.
Shape: shape, conductor lines, insulated handle and lining board combination should comply with the regulations of drawings or provide samples.
Conductor and pinhole defect: according to the following chart to determine standard, within the scope of each of the 50 mm allows a.
Carbon ink: cover the silver paste on a line of carbon ink, should ensure that completely cover the silver pulp, the thickness of 8 to 10 microns, can not have very obvious protruding silver pulp.
Stamping burrs and die extrusion bending size: stamping burrs and crowded bending size, should not be greater than 0.2 mm, and no conductor position should be facing a side.
All: membrane switch contact shall not have any ink adhesion, insulation insulation ink face should level off, to avoid any bubbles or pinhole defect and influence of insulation effect.
Combined state: chip surface must not have residual materials, foreign bodies, stain, concave and convex and attached to the surface and the fats, fingerprints, coining of burr shape on line.
Scar: all lines and contact shall not be cut through table (that is, the cut on the line cut to base material), slight abrade also does not affect the impedance as principle, carbon ink surface scratch have an extremely easily, the scratch will not affect the circuit conduction as criterion.
Adhesion strength: insulation dry ink, the ink surface abutting again after 24 hours, the weight of each other to ensure that the insulation is not stick to each other.No bubble with a pressure sensitive adhesive tape attached with a hand pressure after 1 minute, quickly, also can not have ink fall off.
Jump line: all jump line department in accordance with the requirements of conductor line and all products are required to pass through 100% jump line open and short circuit test and insulation resistance testing.Make sure there are no any open, short circuit and insulation resistance should be greater than 500 m Ω vdc1 (500 minutes).