Membrane Switch


	INTRODUCTION The graphic layer of the membrane switch should not only be aesthetically pleasing, it must endure use in its environment. Since environments vary greatly, the proper faceplate material must be chosen. Hankuk Polytech has a variety of materials fully tested and categorized for almost any environment. In most cases the faceplate for a membrane switch is printed on a polyester or polycarbonate material. Polyester is more resistant to chemicals found in industrial settings and is better suited for use with tactile feedback switches because it will not crack over time. Polycarbonate is optically clear at any thickness, provides a crisper emboss and will operate at a higher temperature.
	DESCRIPTION A membrance switch is a normally open,momentary contact device made up of three layers. The top is a flexible with movable contacts screened layer. These two layers are separated by aninsulator through with openings are cut at the aligned contact points. When pressure is applied to the top contact,the film,or membrance,flexes toward the stationary contact until the circuit is then broken when pressure is removed and the membrance returns to its normally open,or seperated,position.Generally an additional layer is laminated to the top circuit. This layer has graphic nomenclature which locates and describes the switch's function.

SPECIFICATIONS Mechanical Life Cycles.............2,000,000 Switch Thickness....... .030" - .050" typ. Switch Travel.......... .005" - .010" typ. (Non-tactile) Environmental Storage.................-40∑C to 75∑C Operating...............-40∑C to 70∑C Electrical Characteristics (Switch Circuit) Contact Resistance: varies proportionately with part size, typically 100 Ohms or less. Resistance values are typical through the life of the switch. Open Circuit Resistance: 5 x 106 Ohms minimum. Contact Rating: 30 VDC maximum, 100mA maximum, 1 watt maximum Contact Bounce: 1ms nominal, 20ms maximum at 3,000,000 activation cycles.
Applications Membrance switches serve as Automotive Industrial Controls Instrumentation Consumer Electronics Telecommunications and Aerospace industry Alarm Remote controls Electronic equipment etc

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