Apple Inc.
Electrical key support membrane

Abstract:

Keyboards and other input devices are provided with membranes that extend under the keycaps or buttons. The membranes are flexible and can support conductive structures, traces, and electrical switch connections to enable effective key switches, lighting, and fluid-tightness for the keyboard. The flexible membrane is positioned near the keycaps to prevent ingress of fluids and debris into the lower portions of the key assemblies. In some cases, the flexible membrane also provides support for an interstitial layer that extends between keycaps.