The Connector Tail of the membrane switch keypad

The position of the membrane circuit tail should be carefully planned as it could have substantial impact on the design of the membrane switch. A minimum clearance of .04 from tail edges for the tracks and a .020 minimum for each track must be allowed. The tail is formed from the circuit layers. Therefore, no feature requiring a circuit track (i.e.switch or integrated LED) can be between the tail exit point and the edge of the panel.The easiest exit location that can be produced is to bring the tail straight out of a panel edge (edge exit). This works fine if a bezel will cover the panel edge. Also easily accomplished is if the tail can exit just inside the panel's perimeter. When the panel fits a recess this is an excellent tail exiting position.

If the membrane keypads tail must exit from within the perimeter (inset exit) then a tail filler must be used to replace the missing circuit layers. Alternatively a WATER TIGHT NEMA 4 type perimeter seal can be utilized at an additional cost when necessary.

The tail is delicate and a smooth route (not sharp bends - .10 minimum radius) should be used.The longer the tail the more likely that electrical resistance and that the cost of the switch will increase.

A male or female connector can be fitted to the end of the membrane keyboard tail. Solder pins can also be provided.A pitch of .10 and .039 is the most common. Using a ZIF type connector will reduce the membrane switch cost as the tail will not need its own connector and the pitch can be reduced to 0.5mm(.02”) to 1.27mm (.05”).Exposed silver should be covered with carbon to avoid silver migration and not be adversely affected by moisture.