Siemens Aktiengesellschaft

Joachim Schimkat

Helmut F Schlaak

Lothar Kiesewetter

Hans-Jurgen Gevatter

Hans-Juergen Gevattter

The micromechanical electrostatic relay has, on the one hand, a base substrate with base electrode and a base contact piece and, on the other hand, an armature substrate with an armature spring tongue that is etched free and curved away from the base substrate, and that has an armature electrode and an armature contact piece. When a control voltage is applied between the two electrodes, the spring tongue unrolls on the base substrate until it is stretched and causes the two contact pieces to touch. In order to obtain a high contacting force given an optimally large electrode area, the armature contact piece is arranged on a contact spring section that is cut free from the spring tongue via spring webs in the form of a sun wheel with spoke sections helically interengaging such that it is surrounded on all sides by the spring tongue.

Micromechanical relay

Micromechanical relay having a hybrid drive

A micromechanical electrostatic relay has a base substrate with a base electrode and a base contact piece. The relay also has an armature substrate with an armature spring tongue that curves away from the base substrate, and an armature electrode and an armature contact piece. When a control voltage is applied between the two electrodes, the spring tongue unrolls on the base substrate and thus closes the contact. The curvature of the spring tongue in the quiescent condition is produced by a coating with a compressive strain layer. In order to avoid undesired transverse arcs of the spring tongue, the compressive strain layer is subdivided into strips by slots in a longitudinal direction of the spring tongue. A tensile stress layer applied in surface-wide fashion over the strips and slots reinforces the compensation effect.

Micromechanical relay with transverse slots

A micromechanical electrostatic relay has, on the one hand, a base substrate with a base electrode and a base contact piece and, on the other hand, an armature substrate with an armature spring tongue that is etched free and curved away from the base substrate and that has an armature contact piece. When a control voltage is present between the two electrodes, the spring tongue unrolls on the base substrate until it is stretched and causes the two contact pieces to touch. In order to prevent a creeping contacting and make the closing and opening of the contact abrupt, a geometric discontinuity is provided in the wedge-shaped air gap between the two electrodes. This discontinuity is formed by a partially curved, partially straight design of the spring tongue, by an offset of the beginning of the electrode relative to the spring attachment, and/or by an air gap between the spring attachment and the base electrode. The result is an unambiguous switching hysteresis with trip events when closing and opening the contact.

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Berlin, Germany

Joachim Schimkat